searching for a specific metafield value not on the Criteria drop-down list

Is there a way to find a particular metadata field value that isn't on the (presumably) fixed Criteria drop-down list?  For example, I would like to find files with the ‘Credit Line’ metadata field having a value of ‘Harvey’ (see attached screenshots).  I know the ‘All Metadata’ selection will work, but I just want to zero in on files with values for that particular meta field. 

In other words, is there a way to add, say, the ‘Credit Line’ metadata field to the Criteria drop-down list?