Smart Albums criteria: Using Folder locations as a search criteria

I would like to expand my use of Smart Albums. One important criteria would be able to point or reference to the physical location of the image on my external drives. I understand that I could use DATE fields to accomplish this but means creating two search criteria; one for the first day of the period being searched along with a second criteria for the last day of the searching period. The other issue is that sometimes I don't use Date Arranged Folders. Is there a more elegant work-around or should this be a feature request.