Camio doesn't get notified when new members have been added to a G Suite Directory Group. Rather than continually requesting group membership, Camio caches your group membership for about 10 minutes. The method to force a refresh of your group memberships differs depending on whether your email address is the same domain or different domain than the host Group.
When your email is same domain as the Group
If a Group doesn't appear in your Search panel (when you click inside the Search box), then use the refresh icon to update the list of Groups available to you:
When your email is different domain than the Group
Your attempt to search a Group triggers the lookup of your membership in the Group. For example, if the group firstname.lastname@example.org has shared with your email email@example.com, then only after you've clicked this link will Camio lookup your membership in the hq-cams Group of the acme.com domain.
(i.e. your request to see results from firstname.lastname@example.org is what triggers the lookup, since Camio doesn't otherwise know a priori that email@example.com is associated with a Group inside acme.com.