Show only elements with a specific id (determened in the url)

I’ve been working on a coding project and I have been trying to have multiple “pages” in one html file (e.g. awsomesauce.com/page.html#videos and showing only the videos section) while having the same navbar and so far javascript has let me down. Any ideas?

<script>
// Get the current URL (awsomesauce.com/page#videos in this instance)
let url = window.location.href;
// Get the length of the current URL
let urlLength = window.location.href.length;
// Extract the portion of the URL starting from index 21
let  = url.substr(21, urlLength);
</script>