create a formula to verify the last week data or sales by entering the formula below.
first you need to create a date with next week... you have a function called DATEADD so in this formula you have option to add one week to existing date... so if the actual date is week1 it will display week2 ... and you have to use this calculated field in formula... that means if you select week3 sales it will actually display week2 sales as the week2 is original order date.
DATEADD('week',1,[Order Date])............ there you go... your problem will definitely solve with this solution.
I think this calculation should work based on your example (sum([Sales]) - lookup(sum([Sales]),-1)) / lookup(sum([Sales]),-1).
Pamela Germain, thanks for your response. I have tried and it has the same issue, i believe in essence your Calculated Field is a Table Calculation therefore when I filter it does not have anything to lookup
suresh.gooty thanks for your response too, could you please expand on how to use DATAADD to bring sales in a different CF?