Revit :: Filtering Schedules By Level?

I have an issue where filtering my framing member schedules per Level by, for example, Level equals LEVEL 3 causes the entire schedule to be filtered to empty.  We clearly have members constrained to and occuring on LEVEL 3.
 
The same happens when filtering for, say, at or above LEVEL 3, but interestingly not at or below LEVEL 3, in which case nothing happens -- that is, it still displays members clearly occuring only on and constrained to Reference LEVEL 5.