Do a search for - constraints

I am trying to figure out how to set up a specific constraint in a “do a search for”

I am trying to send data to a repeating group and I want to include records where “field A” = “field B”. Or remove from the list those records where “field A” <> “field B”. I cannot find any function to do this.

I can select “field A” and then select “=” but then there is no option to select another field in the same datatype to compare it to.

Am I missing something or does this function not exist?