Calculation with filtered data range

[chaiwaykeat]

How to create a column where the expression of the column will be to only be average of the past 3 month avg yield rate (billing month)  from the dock date for example if the dock date is 2020 Jan than the data use to calculate will be (0.60+0.66+0.68)/3

[Rodj]

I'm not sure I understand properly what you are trying to do. Are you trying to get an average for the 3 most recent months per dock date yearmonth, or are you after a sliding type average regardless of the dock date?

This sounds like something RangeAvg would be good for, something like:

rangeavg(above(sum([Avg Yield Rate]),1,3))

This will give you a sliding average result, I've used above for the 3 most recent records, but depending on your sort order you can change that to Below or whatever is appropriate.

Hope that helps somewhat.

Rod