Yes! I have it on the following settings:

• Privacy: Anyone can see the group, who's in it, and what members post
• Membership Approval: Any member can add or approve members

which are the least restrictive options in both categories.

If someone (who was not already invited and approved by a member) asks to join the group, it pops up a notification for me to approve them, but I have approved (and will approve) all requests that aren't obviously spammers.