The manage filters-->search tab lacks usability, I don't understand how to use it

The search tab on the manage filters page is kinda confusing, when you open it you notice a pair of fields to the left, a huge amount of horizontal white-space and then a user picker to your left.

It is really unclear whether the user is supposed to enter data in all the fields or in one of the field "groups"(even though there is only one search button :-S) to perform a search. See screenshot.

It seems like this form needs a bit of JT / UX / Usability love.