If you wishes to display list of connected users for a domain (with additional filtering), you should click on
Get Connected Users.
It will present you with a following form, allowing you to select domain.
Filter field, you may a text which should be part of the displayed users jid. There is no pattern matching - you only enter part of the jid which you are looking for.
This will narrow your search and reduce number of displayed entries.
When you submit this form, you will be presented with a results in the form similar to the one visible on this screenshot.