Duplicates don't show in smart group

In one particular database, I have a large number of duplicates, which show in blue and bold type in their respective groups. But the “Duplicates” smart group which was automatically created with the database shows no duplicates at all. Any thoughts on why this would be? (I’ve checked and the smart group criteria appear to be correct, i.e., “kind” = any content, “instance” = duplicate.)

What’s selected in the “Search in:” pop up menu? Please note that unread links could also be blue & bold, the final release will use a different appearance to fix this.

Thanks for the quick reply…and the sound instincts: I had a single folder rather than the database id’d in the “search in” pop up field. Problem solved.