Assigning roles to all users in a group

How do I assign roles to a specific group, not to a specific user, and apply the roles to all users in that group? This particular group has four users.

This is possible in the SAP portal for portal roles but I defer to others for more specific guidance for SAP portals. Assigning roles to groups in the ABAP stack is a concept that SAP abandoned. It cannot be done in current versions of Netweaver. It may be possible in some earlier versions but the functionality was always problematic and ultimately SAP withdrew it from support.