For all types of groups (Public, Closed and Secret) members can add people they are friends with on Facebook. You can also invite supporters you’re not friends on Facebook with by clicking Invite by Email in the top right of your group to send an email. Another way to attract group members is by talking to people off of Facebook. If your group is public or closed, they’ll be able to send a request to join.
To add new members to a group:
- Go to the group.
- Click the + Add People to Group field in the right column.
- Type your friends’ names and click on them to add them to the group.