Is there a sample workbook that you can attach?
No, this option of selecting how totals are calculated directly does not appear in my case because variable X includes data from blended sources. I cannot attach a copy of my original data as it is confidential. However, I can give you any clarification you need. I kinda new to Tableau and thus I cannot think of any solution about this issue, as when I apply AVG function to the totals of X it does the avg of the sum of the elements, and I want the sum of monthly averages (cannot use LODs though in order to keep the rest of the view).