How to manage datasources in DevExpress Reporting for Web?

I have a project on .net core that uses CRM. The user can configure different forms with different fields. Each field has some mapping to db field. Forms are grouped by modules. I would like to display those forms as list of datasources. With this no problem in case there are not a huge amount of forms. I can do like this:

var designerRender = Html.DevExpress().ReportDesigner("reportDesigner")
        .ClientSideEvents(events => {
                                   events.ReportOpening("onReportOpening");
                                   events.CustomizeOpenDialog("customizeOpenDialog");
                                   events.CustomizeSaveAsDialog("customizeSaveAsDialog");
        })
        .DataSources(dataSources =>
        {
            // Add the created data source to the list of default data sources.
            foreach (var dataSourceItem in Model.DataSources)
                dataSources.Add(dataSourceItem.Key, dataSourceItem.Value);
        });
    @designerRender.RenderHtml()

Model.DataSources is filled in the controller.

But what I would like to – I want to display forms grouped by modules. Only when module is expanded, I want to load list of forms for that module. And when form is selected – load all components from that form.

In the documentation, I cannot find any event/method that can be customized for that purpose. Can you help me?