This is something we really need because we have a lot of private forums and it's essential that we are sure that the right people have the right access to forums... and that those who shouldn't have access, don't. The way it is right now, there's no way (that I know of) to see a list of users (primary or secondary) in a particular usergroup. Because we have a lot of private forums, and because of the way XF works, we think the easiest way for us to do it is to use a lot of usergroups (one for every private forum) and use them to show what forums a member has access too (by giving them secondary usergroups that correlate with what private forums they have access to). In order to carry out our regular checks to ensure those with access to private forums that have particular participation requirements are meeting those requirements, we need to know who is in what usergroup (ie. who has access to what private forum). If someone could make an addon that allows us to click on a usergroup in the usergroup list, to see which users have that usergroup as primary or secondary, we would be so grateful!