Specific User Page assistance

I currently have RLS setup with my dashboard which works great. However, I've been asked to add another layer for a page to be created which will show the user their data only without the needs for manual filtering. 

So, they'll be able to view the company as a whole, dive into their site data (via RLS), but then open up a page which gives them direct access to their data/visuals to which they can make decisions on & they can't see other users data (or at least without trying very hard

I've tried my best with ChatGPT and USERPRINCIPALNAME being used in various measures but nothing seems to work. The data either shows blank or doesn't filter down.

Does anyone do this in their report?