The “Search results” panel seems to not keep the 'Filter for' value and produces confusing results for the user.

Search for anything in the upper right hand corner. Say the string “foo”.
The “Search results” panel opens with “foo” and Filter for: “Everything”, and a non-zero list of results.
Switch the Filter for to any other value and click Search.
  Either “nothing happens” ( no page repaint, search set is the same..)
    OR
   Filter for is reset to “Everything” and you get a search set for the “previous” value of ‘Filter for’ ??!!?It is just not working right….

Actually I think the 'Filter for' value is being “reset” to “Everything” after every search.

  So set it to “Folders” click search.
     I am now getting the results of “folders”… but the 'Filter for' value is also being reset to “Everything” as well. No errors in the javascript “console” AFAIK. 
 
 
If you manage to “double click” the search button then you would not get the list you wanted. What appears to happen is the 'Filter for' value is reset to “Everything” and you get that list back.