I just stumbled upon this during my work on OFBIZ-9440.
As Amardeep said, the functionality is incomplete. For the average user, the query widget pretends to provide a search functionality but there is nothing more than this widget (like Pierre rightly mentioned providing the patch).
I see no reason why this work was committed in this state because it only causes confusion. We should definitely be more cautious when adding new functionality to the codebase.
In a case like this, we should have waited until the work provides a minimum of functionality and ist tested accordingly.
I will add this as a subtask to the refactoring issue and work out a minimal functional solution in the course of this work.