RLS with two authentication ID's

Hi,

I am having an issue with my RLS implementation. 

I have a table with two unique identifiers, namely merchant code and email.  A merchant code can have multiple users and the users can be linked to two merchant codes.  The first identifing factor is the merchant code and then the email address.  Creating the RLS for the email as simple using dynamic the userprinciplename DAX expression, but I am not sure how to combine them. 

I have tested the email RLS and it is working but it is returning information for both merchant codes that it is linked too.

I have the fact table that is linked to the merhcant code bridging table and then the full table with the merchant codes and emails.  Hope some one can assist.