Table Visualization: Using calculated column to run formula on columns from two tables

Hi All,

I'm not very familiar with DAX and am struggling to combine data from two tables in a table or matrix visualization. The two tables in question do not have a direct relationship to each other, but rather through a third table. However when I try the RELATED function to pull in values from one or the other, the relevant tables are not available. Even when trying RELATED in the third table that should link them both, neither is available. 

The end goal is to have something like:

= 'Table1'[Column4]/'Table2'[Column2]

The table visualization itself does display data from both my tables, although I'm having another error there. I don't have data in both tables for the entirety of the time period, but the table appears to be multi-matching the available data to all points in time.

Any suggestions?

Thanks