Relationship Between Multiple tables to create a check

Hello,

I am not sure how to word my question, or if it is possible. 

Currently I am working on a data set and i have a total of 6 different tables. It is hard to explain the relationship, but i will try.

I have one table that encompasses all of the data that I want to reference. Essentially it is a trade desk, a product and an underlying product. 

I have a second data set that has all of the same details, but they are in a different format, which require mapping. So I have a mapping table that will take a code from the second data set and assign it a desk. Simillarly I have two mapping tables that will take a code and assign the second data set a product and underlying product. This relationship works great as I can create a table visual and see everything together in the same format as table 1. 

Now my issue comes when comparing the two tables. I don't know how to ask, but how can I compare one table that has everything to a second table that hold none of the same values without mapping? My table visual shows them all together, which makes me think it should be simple, but I don't think it is that simple. 

This is what my relationship tree looks like.