You’ll need to provide greater specifics about which tables are joined to which, and where you want the restrictions applied. But most likely, at the very least, you’re going to have to modify your universe in Designer to force Table X (the group table?) to be used with each object in Table Y (the fact table) – by using the “Tables” button on the bottom of each object that you want to force.
You can also read this presentation from Bob’s Downloads.
I am moving this topic from “Security and User Administration” ==> Supervisor (4.x -6.x) to the “Semantic Layer” forum, because that’s where the discussion should most likely continue.
Anita Craig 
(BOB member since 2002-06-17)