Displaying filtered list in display form

I have a fairly straightforward requirement that I need assistance with.

I have List A and List B. When viewing the Display Form of List A I want to view items of List B when 2 fields match. I know I can add a data view web part of List B, but I'm not sure how to filter it so it only displays the list items of the matched fields.

Note that these lists are not tied by a relationship.

Thanks for any assistance you can give.

Scott