Group members who do not hold the "owner" or "admin" rank do not have access to the group dashboard. If they attempt to view the dashboard page, they see this message instead:
Additionally, group members who are not owners are not allowed to go through the registration form and change their memberships. This is to prevent them from removing themselves from the group. Their membership is already managed by the group membership. If they try to go through the registration form, they will see the following:
Note: If you have Multiple Memberships enabled in Restrict > Settings > General, then group members are permitted to sign up for their own membership. They would then be a group member and hold their own independent membership simultaneously.