I am struggling a bit with one thing. I want to find a way to write a set analysis to sum up every month's previous month's sales. My sales data is on a monthly basis and I have managed to set up a flag to capture (IS_Previous_Month) in order to get a snap shot of what was previous month's sales for just this time period right now, so to speak. However, I would like to be able to select in a bar chart for example February 2018 and see Sales of January 2018.
The reason for this is that I am about to develop another KPI later that involves every selected time period's previous month's sales.