There are couple of ways to do so.
1st solution, use grand total as FFF
step 1, create calculation field
step 2, build the view and set up the table calculation
Solution 2, union your data to itself.
step 2, create calculation for filter, and exclude the null values
Workbook attached for your reference.
Hope this helps
Book20_v10.2.twbx 18.4 KB