Allow only admin to add new member in new group

Product Support
2

Might need more info

If you make it a closed group. You can make the group visible.

Members in the group that are made “Owners” can manage group membership.

There are options to make set group interactions. & Access.

The image shows membership and access settings for an online group, including options to allow users to freely leave the group, send membership requests to group owners, and a custom template displaying "Subscribe to Planet Pimax!" when sending a membership request. (Captioned by AI)
The image shows membership and access settings for an online group, including options to allow users to freely leave the group, send membership requests to group owners, and a custom template displaying "Subscribe to Planet Pimax!" when sending a membership request. (Captioned by AI)864×857 125 KB

And interaction

The image shows various settings and options for managing visibility, interaction, posting privileges, and notifications for a group or community on what appears to be a messaging or collaborative platform. (Captioned by AI)
The image shows various settings and options for managing visibility, interaction, posting privileges, and notifications for a group or community on what appears to be a messaging or collaborative platform. (Captioned by AI)864×1664 162 KB

With these settings set appropriately. An owner can boot a member when needed & with Category security settings will not be able to post in those group access categories.

Owners of a group are the so to speak group admins.