Two Dataset Column fields from one Dataset without duplication

I have two Dataset Column fields that reference the same Dataset. Both are spec’d to produce Arrays:

Field Names
foo.bar[1-2]
foo.baz[1-5]

Dataset
A, B, C, D, E, F, G…

I’d like to limit foo.baz to ONLY the values of the Dataset that have not been used in foo.bar (in that instance). Can I do that?