Hi @RajNadar, the expected result, from the above calculations, won't come as 'beast modes' are calculated on a row basis. With this beast, either there will be values from current month or previous month but won't have both captured. As a result, you'll have a value and NULL per row and also subtracting null from anything will give null, resulting in a blank output.

Using Window functions are one option to look into for your calculations, whether it's through Analyser or ETL.