Hi Tom @tomDG,
What Erik is said above is right.
To fully answer your question, session tags can’t be mocked in analysis view. After turning on tag based RLS, you have to apply user based RLS on the data set to be able to see data from analysis view. You can either give yourself or your author group full access or change that around as needed (by updating the user based RLS rules). In my opinion, it is easier to work with full access (if your org allows it); You can always mimic end user view by slapping on temp filters or generating embed urls with desired tags passed in.
Regards,
Arun Santhosh
Pr Quick Sight SA