We are trying to make it easier for our customer

We are trying to make it easier for our customer to administer their site, they have lots of "groups" of members which they want to check and manage, but currently the "All Members" page is listed alphabetically.

If I had a custom field which was the "group" that member belonged to, is there any way to alter the "All Members" page to sort by that custom field? And/Or can we add a "filter by" for groups?

If this page was compatible with "Admin Columns Pro" I could do it, but it doesn't show up in that list.

In fact this would all be sorted if there was a way to use the standard "Users" page but also get the features of the "All Members" page - listing subscriptions etc. Is that possible?

Note that I'm not talking about buddypress or any other "group" plugin, I am just going to use custom fields here.