Analysis :: Relating Multiple Fact Tables To Find Data That Exists In One But Not The Other

I'm currently setting up a Tabular Model to do some research between several fact tables.  In this example i have two fact tables (table 1 and table 2) which I've created a 1 to 1 relationship on phone number.  Typically I create a relationship between these tables to find common data between the two.  However, in this case I am trying to figure out the best way to model the data so that I can easily surface data from one table that does not exist in the other.  I would liken this to a LEFT JOIN or a WHERE NOT EXISTS in SQL.

Table 1 has all of the data and Table 2 Only has a subset of the data from Table 1.  What I'm trying to do here is display what attributes in Table 1 may play a part in records not existing in Table 2. What is the best way to model this?