Add Third Select Drop Down and Auto Populate Based on Selection

I have made a request form for my group to make it easier for them to request for help desk. At the moment I have two dropdowns – I have the main request dropdown when the user selects from the first dropdown selection it goes to the second dropdown selection for the user to select. I want to add the third dropdown so when the user selects from the second dropdown it opens more selection in the third dropdown based on what category the user has selected for the Second dropdown.

How can i add third select option and then show the input for the selection

$(function() {
    // on page load wrap all select-2 options in span so they cannot be selected without specifying select-1
    $('#select-2 option:not([selected])').wrap('<span/>');
});
// when select-1 is changed, hide all options that do not have the class corresponding to the value of select-1
$('#select-1').change(function() {
    $('#select-2 span > option').unwrap();
    console.log($('#select-1'));
    $('#select-2 option:not(.' + $('#select-1').val() + ', [selected])').wrap('<span/>');
    //console.log($('#select-2').val());
});

$('#select-2').trigger('change');


$(document).ready(function() {
    $("#otherFieldGroupNewacc").hide();
    $("#otherFieldGroupMod").hide();
    $("#otherFieldGroupRes").hide();
    $("#otherFieldGroupRem").hide()
});

//----------------------------------Second Dropdown----------------------------------------------//
$(function() {
    $("#select-2").change(function() {
        if ($(this).val() == "AS400 New Account") {                                 //AS400 New Account //
            $("#otherFieldGroupNewacc").show();
            $('#otherFieldGroupNewacc').attr('required','');
        } else {
            $("#otherFieldGroupNewacc").hide();
            $('#otherFieldGroupNewacc').removeAttr('required');
        }

        if ($(this).val() == "Modify Account") {                                    //AS400 Modify Account //
            $("#otherFieldGroupMod").show();
        } else {
            $("#otherFieldGroupMod").hide();
        }

        if ($(this).val() == "Reset Password") {                                     //AS400 Reinstate Account //
            $("#otherFieldGroupRes").show();
        } else {
            $("#otherFieldGroupRes").hide();
        }

        if ($(this).val() == "Remove Password") {                                     //AS400 Remove Account //
            $("#otherFieldGroupRem").show();
        } else {
            $("#otherFieldGroupRem").hide();
        }
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="form-group">
                    <label>Request Type</label>
                    <select id="select-1" name="select-1" class="form-control w-100" required>
                        <option selected value="">--Select an option--</option>
                        <option value="AS400">AS400</option>                                     <!-- "option-1" -->
                        <option value="EETV">EETV</option>                                       <!-- "option-2" -->
                        <option value="Outlook">Outlook</option>                                 <!-- "option-3" -->
                        <option value="Windows">Windows</option>                                 <!-- "option-4" -->

                    </select>
                    <br/>
                    <label>Choose a Sub-Category</label>
                    <select id="select-2" name="select-2" class="form-control w-100" required>
                        <option selected value="">--Select an option--</option>
                        <option value="AS400 New Account" class="AS400">New Account</option>                  <!-- "option-1a" -->
                        <option value="Modify Account" class="EETV">Modify Account</option>                        <!-- "option-1b" -->
                        <option value="Reset Password" class="Outlook">Reset Password</option>                        <!-- "option-1c" -->
                        <option value="Remove Password" class="Windows">Remove Account</option>                       <!-- "option-1d" -->
                    </select>
                </div>
                <hr>
                <!--AS400 New Account-->
                <div class="form-group" id="otherFieldGroupNewacc">
                    <h2>AS400 New Account</h2><hr>
                    <div class="row">
                            <div class="col-6">
                                <label for="userRequestor">Full Name</label>
                                <input type="text" class="form-control w-100" id="userRequestor" name="userRequestor" placeholder="Type Here..." >
                            </div>
                            <br><br>
                        <div class="col-6">
                            <label for="userTM">Beneficiary (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userTM" name="userTM"placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userEmployee">Employee ID</label>
                            <input type="text" class="form-control w-100" id="userEmployee" name="userEmployee" placeholder="Type Here...">
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="selectJob">New Job Category</label>
                            <select id="selectJob" name="selectJob" class="form-control w-100" placeholder="*Click in box for Job Category List*">
                                <option disabled selected value="">Select an option</option>
                                <option value="NO CHANGE">NO CHANGE</option>
                                <option value="ADMCLK = Admin Clerk">ADMCLK = Admin Clerk</option>
                                <option value="ADMCLK+ = Admin Clerk w/ Manual Book">ADMCLK+ = Admin Clerk w/ Manual Book</option>
                                <option value="ADMMGR = Admin MGR w/ Manual Book">ADMMGR = Admin MGR w/ Manual Book</option>

                            </select>
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="userNewAS400">New AS400 ID</label>
                            <input type="text" class="form-control w-100" id="userNewAS400" name="userNewAS400" placeholder="Type Here...">
                        </div>
                    </div>
                </div>
                <!--Modify AS400 Account-->
                <div class="form-group" id="otherFieldGroupMod">
                    <h2>AS400 Modify Account</h2><hr>
                    <div class="row">
                        <div class="col-6">
                            <label for="userRequestorMod">Requester (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userRequestorMod" name="userRequestorMod"placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userTMMod">Beneficiary (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userTMMod" name="userTMMod" placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userEmployeeMod">Employee ID</label>
                            <input type="text" class="form-control w-100" id="userEmployeeMod" name="userEmployeeMod" placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userAS400Mod">AS400 ID</label>
                            <input type="text" class="form-control w-100" id="userAS400Mod" name="userAS400Mod" placeholder="Type Here...">
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="selectJobsMod">New Job Category</label>
                            <select id="selectJobsMod" name="selectJobsMod" class="form-control w-100" placeholder="*Click in box for Job Category List*">
                                <option disabled selected value="">Select an option</option>
                                <option value="NO CHANGE">NO CHANGE</option>
                                <option value="ADMCLK = Admin Clerk">ADMCLK = Admin Clerk</option>
                                <option value="ADMCLK+ = Admin Clerk w/ Manual Book">ADMCLK+ = Admin Clerk w/ Manual Book</option>
                                <option value="ADMMGR = Admin MGR w/ Manual Book">ADMMGR = Admin MGR w/ Manual Book</option>
                                <option value="DCM = DC Manager">DCM = DC Manager</option>
                                <option value="FM IN = Inbound Funtion Manager">FM IN = Inbound Funtion Manager</option>
                            </select>
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="userNewAS400Mod">New AS400 ID&emsp;<strong>***Leave Blank If No Change***</strong></label>
                            <input type="text" class="form-control w-100" id="userNewAS400Mod" name="userNewAS400Mod" placeholder="Type Here...">
                        </div>
                    </div>
                </div>
                <!--Reinstate AS400 Account-->
                <div class="form-group" id="otherFieldGroupRes">
                    <h2>AS400 Reinstate Password</h2><hr>
                    <div class="row">
                        <div class="col-6">
                            <label for="userRequestorRe">Requester (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userRequestorRe" name="userRequestorRe"placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userTMRe">Beneficiary (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userTMRe" name="userTMRe" placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userEmployeeRe">Employee ID</label>
                            <input type="text" class="form-control w-100" id="userEmployeeRe" name="userEmployeeRe" placeholder="Type Here...">
                        </div>
                        <br><br>
                        <div class="col-6">
                            <label for="userAS400Re">AS400 ID</label>
                            <input type="text" class="form-control w-100" id="userAS400Re" name="userAS400Re" placeholder="Type Here...">
                        </div>
                    </div>
                </div>
                <!--Remove AS400 Account-->
                <div class="form-group" id="otherFieldGroupRem">
                    <h2>AS400 Remove Account</h2><hr>
                    <div class="row">
                        <div class="col-6">
                            <label for="userRequestorRes">Requester (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userRequestorRes" name="userRequestorRes"placeholder="Type Here...">
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="userTMRes">Terminated TM (Full Name)</label>
                            <input type="text" class="form-control w-100" id="userTMRes" name="userTMRes" placeholder="Type Here...">
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="userEmployeeRes">Employee ID</label>
                            <input type="text" class="form-control w-100" id="userEmployeeRes" name="userEmployeeRes" placeholder="Type Here...">
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="userAS400Res">AS400 ID</label>
                            <input type="text" class="form-control w-100" id="userAS400Res" name="userAS400Res" placeholder="Type Here...">
                        </div>
                        <br>
                        <div class="col-6">
                            <label for="hideInputRes">Reason</label>
                            <input type="text" class="form-control w-100" id="hideInputRes" name="hideInputRes" title="Example: Fired, Retired, Leave of Absence, etc..." placeholder="Type Here...">
                        </div>
                    </div>
                </div>