OS X :: How To Add Column Headings To Finder Window

I'm running Mac OS X 10.5.6 (9G55) with Leopard. On a typical work day I'll open Finder to look for pdf files. I'll perform my search for pdf documents and, as expected, all pdf documents that exist on my Mac are listed in Finder. In the Finder dialog box there are headings at the top of the columns that include "Name", "Kind" and "Last Opened". When I single click on any one of the listed pdf documents, the path to that document's location is given at the bottom of the Finder window. Every month I save hundreds of different pdf documents in about 135 different customer file locations.

As a result, I need to be able to add a column heading that orients the results on a file location basis. On my former XP I could add many different headings, including one that simply stated "Filed In" (or something along those lines). By clicking on the heading "Filed In", all of the pdf documents would be grouped and listed by their file location. My question is: Can I add a "Filed In" heading to the search results window of Finder so that I can click on "Filed In" and group search results by the file locations?