Hi Sam,
I have worked my way through this rather complicated formula and it is quite brilliant but has a bit of a shortcoming.
Firstly, the total is wrong. In this example, it should be 426, not 412.
The second thing is that I need to reference the result of this in other measures, but now since we have removed the month filter from the calculation, I am getting incorrect results.
As a rather crude example, say I need “Chosen Sales Values”
Chosen Sales values = [Reverse Cumulative]
If I put this in a table against sales levels I will only get the full total, not the total of the chosen levels as I do not have the correct filter context
See attached
Testing Reverse Cumulative.pbix (305.5 KB)