Allow display rules to apply table columns imported from related objects

I have numerous tables which contain columns from related objects. I really like the “display rules” feature, but currently can only set display rules based on variables found in the original object.

Object A contains a list of customers and Object B contains phone numbers. If I create a table based on Object B, Knack lets me display data in that table from Object A. I can set “display rules” for any data contained in Object B, but none for Object A.

I am interested in being able to set display rules for any column of a table regardless if it comes from Object A or Object B.