The search criteria are the same as pruning.
Once you submit the search form, you will be asked whether you wish to move all threads that match your criteria or want to move threads selectively. If you chose to move selectively, you will be shown a page similar to this:
This lists each of the threads that matched your criteria. Use the checkbox on the left to select whether or not the thread is moved. Once you are ready, click .
Once the moving is complete, you should run Rebuild Forum Information in Update Counters.