Hi Celine, check out this video https://www.youtube.com/watch?v=CAZ3IAJEuCI and forward to the part dealing with the second workbook tab (Time Shift), which may help you out. It involves duplicating and blending, and how to time shift a data source.
Thanks Glenn, I'll have a look now.
In the meantime, I have been working with the table calculations, I think there might be a piece of solution as well.
I managed to get a full matrix with the information that i want.
From this matrix, I would just like to be able to use a filter to extract the information for a specific month.
I used a simple filter on the matrix but of course, it's just giving me blank values as my calculations are "based on the previous value in the table".