Create admin roles and set permissions
You can create numerous administrator roles within your group settings. You can also name the roles e.g "coach" or "helper". The Group Manager will by default have all permissions available. If an admin has permission to for example create events, they will be able to do so in all sub groups within that group as well as access all the sub groups. All admins will be able to see the members contact information.
To add new admin roles go to the group, press the three dots in the menu and "settings" > Roles and permissions > Add administrator roles
To edit all members permissions go into each of the member or admin roles and set the permissions
(Example from desktop)