How to access other groups in Sharepoint

Hi Everyone,

I have created few groups (a1,a2,a3,a4) in my sharepoint site. In which (a1) has full control permission and (a2,a3,a4) has contributor permissions. Now some of the users from a1 group want to view/edit the other groups i.e. (a2,a3,a4). Already a1 has full control permission even though they are not able to access other groups. Kindly help me.

Thanks in advance.

regards,

Raj

Raj-pb