[xwiki-users] How to Configure the search user functionality for a given user group?

Hi All, I have question regarding search functionality i want to give rights in a way so that the users in a certain group should be able search the users of a certain group. For example i have 3 groups G1,G2,G3 . G1 contains user U1,G2 contains user U2 and G3 contains user U3. Now i want to give the the group 1 users rights in a way so that they should be able to search the G1 and G2 users only but not G3 users. I know we can customize the rights of specific group user for a specific space but what about above feature? Is it configurable? Thanks .