I was hoping that you could help me with to fix rolling 3 months sales in the same chart as number of complaints for each month. I think it's easier when you have a look at the attached file, where I have used your sample app and done some modification.
I have little different scenario but in extension to this. I have a Master Calendar with Year_Month, Year and Month columns. I have a sales table which has start date, end date and sales column. I want to have rolling 13 months chart for both start date and end date when user selects Year_Month from master calendar.
sum(sales as per start date) - sum(sales as per end date)