Situation : - I want to restrict the access of Lead & Opportunities menu based on the potential users of the system. Consider a system with 10 users , out of which only 6 users should be able to view only Leads menu and remaining 4 users should be able to view only Opportunities menu.

Current system allow a user to access both Leads/Opportunity for Groups / Sales / User: Own Leads Only
and its Rule is as follows ['|',('user_id','=',user.id),('user_id','=',False)], but it doesn't serve my need of hiding menu's.

Can anyone suggest a way to re-define the rule for restricting the access rights of a way to hide/disable menu's based on the user.?? Any help is appreciated ..... Thanks in advance ....