Hi @Steven Timothy8
At this point, permission to create a new group is defined in one place only. That's in Admin Settings > Groups App > "Who can create a new group?", it's a community wide-setting. Meaning if you select Members, then all member can create any types of groups, including Secret group.
As a best practice, to ensure that your community is regulated, we recommend that only Admins have the option to create a new group. You can create a discussion or poll questions discussing what groups your members would like to see. The answer that gets the most likes will be added by you (as the community Admin). Then, you can assign a group moderator/group admin to the specific group only. You can learn more here9
If you are decided to give your members permission to create any type of group, you may do so. As the community admin or moderator, you should be able to access all the groups inside the community to manage and moderate the community.