Admins, Moderators, Groups admins, and Group moderators6 are able to add or remove the community users to/from a group.
1. If the person is already a community member, go to the group page, search for the user's name or username in the "Add Member to Group" section, when the system finds the user click on the name to be added to the group.
Please be advised that the group members can leave the group at any time.
2. If the person you want to invite to a group is NOT already a user in the community, you can use our API documentation to invite the new member right through a group. This way, the person will be a community member and a group member at the same time. You can find our API here247.