This article talks about group.manage_members, CMP out-of-the-box permission.
By default, group.manage_members permission is attached to the Group Admin role. You can define the same permission to a custom role to enable the role to manage other group members.
The group.manage_members permissions enable a role to manage ONLY the existing users in the group, it will NOT allow the role to add a new user to the group.
Step 1 Create a Custom Role And attach the group. manage.members permission
As a super Admin, navigate to Admin-> Role
Create a custom role
Step 2 Attach the custom role to a user
As a Super User, navigate to groups
Select desired group i.e ‘Bonds’, where you want to add your user to be able to manage other users in the group
Now, when ‘testing’ user logs in CB, the user should be able to manage other users in the Bonds' group.