How to test RLS for all reports that share a single dataset?

hi Jhu23, 

I tested the particular scenario and I am able to toggle between 2 reports - 1 built on the data model and another which is using the same data model as a shared dataset. 

If you have assigned users to the different security groups then you would need to assign similar security at report level as well so users just see the report they need to see. 

Please mark the post as a solution if my comment helped with solving your issue. Thanks!