Cummulative Sum of all records but Want to view Last few Results in graph (grouped by month)

I want Cumulative Sum of all records but only want to view Last few Results (grouped by month).
For example If I want to see payable or receivable of anyone then it is not necessary to visualize old values, but I want them to be added in the results I’m seeing (if I use cumulative sum). Does anybody know how to do that?
If I filter the data, it shows the graph but then it misses the old values which I need to be added.
I thought I can achieve this by this option Screenshot_2018-11-15%20Question%20%C2%B7%20Metabase
But unfortunately, it is not producing those results.

2 questions next to each other on a dashboard would surely do the same?

I think I didn’t convey my question very well :sweat_smile:
Actually I just want to view specific points of my graph in the dashboard, without changing the data overall, because I’m using cumulative sum which Metabase provides us (It is a great feature of metabase thumbs up for this :smile: ).
For example;
This is the result of my question using cumulative sum Screenshot_2018-11-15%20Question%20%C2%B7%20Metabase(1)
and I want to view only last 6 months in the dashboard (without affecting the results).

Ah, I understand. I could do that with some SQL, but not easy.