No ideas...I need help.
Hi Frank-Michael Idrees,
Are you trying to do all your calculations before you import data in Tableau? I would suggest using parameters.
You didn't share any data except for the screenshot, so I can't show you how to do it with your data. I've had a similar question in the past, here is my solution for comparing current period vs previous period. If you scroll to the bottom, you will find the workbook embedded in the page. Fill free to download it and play with calculations.
Combining parameters and calculations provides for a more flexible solution. You can choose to let your user select the time period they would like to compare, or you can choose to not display the controls and set a default time period.
Let me know if it helps or you have any questions!