security in project management to view projects for a single OU only

Hi

Client is has two distinct business groups. Underneath each business groups there are multiple OUs. Projects created in an OU uder business group A need not be able to view any projects residing in an OU under business group B. We created security profiles which includes the OUs under BG A and also exclude the OUs under BG B, and a second security profile which is set with including all OUs under BG B and excluding all OUs under BG A. For BG A I set the MO Security Profile with include all OUs under BG A,exclude all OUs under