With the BP Private Community pro plugin, You can restrict the user roles from creating a new group.
To access these settings navigate to, WB Plugins >> Community Pro>> Membership Restrictions, And select the user role from the dropdown.
Scroll down and open the tab Group Restriction >> Group Creation, and access the following settings
- Disable Creating New Groups: This role cannot create new groups.
- Disable Public Groups Creation: This role cannot create public groups.
- Disable Private Groups Creation: This role cannot create private groups.
- Disable Hidden Groups Creation: This role cannot create hidden groups.