To view the membership types and permissions assigned to each role in your group, navigate to Control Panel > System Administration > Group Administration > Groups > (group name) > Edit > Permissions. Lists of available permissions and granted permissions are displayed.
Public and private groups have three group roles. (You can't add a new group membership type.) By default, each group role has tailored permissions. You can change these permissions in the group you edit. And if need be, you can revert the role's permissions to site defaults.
The three types of group roles are:
Each group role has default permissions as listed in the table below.
If your group is joinless, you don't need to manage group membership because the group by definition has no members and makes all content available to users based on site-wide roles, not group-level user types.