I wish to add a total sum column to a pivot table by creating a calculated field column in Excel. I am struggling with how to reference columns in my pivot table as I have two indexes for this particular pivot. I can create the Total column without issue in a pivot table with one row of headers. 
The column headers in question are circled here, is it possible to reference these in a calculated field?
I have tried the following formula to create a Calculated Field without success:
(Count of Outcome_1(Fail)) + (Count of Outcome_1(Pass))

