[GIS] Selecting multiple variables by Attribute from different target layers

Question

I have a model with species point data as a source layer and a number of different shapefiles as target layers. To start I run a search by location tool to determine where the source and target layers intersect, and then copy features to create a new target layer. Next I want to use the select by attribute tool to determine where in my original target layer are common attributes to my new target layer.
My question is: Is there an SQL expression that would allow the search by attribute tool to select from an individual field in the new target layer and compare it to the original layer?

Answer 1

Union the layers and then select by attributes where FieldName = FieldName_1 (if they are named the same then the second input will automatically be renamed with an '_1' suffix).