I have two accounts. One I use with full access the other I use as a simulated user. From the full access account, I can go to USERS > (Locate user) > Add User to Multiple Groups > Add the groups and I can pretty much move the user b/w groups and see the results immediately in a separate browser. I noticed, that suddenly I see two groups regardless what group the user account is placed in.I tried logging out and back in but now the user account always see these two groups that are not shared with the group the user is part of. I did open a case for this: 6266839