Compare differences between data in different groups (year, year/month)

Compare differences between data in different groups (year, year/month)

Hi, I need to compare data in a pivot table. I found articles related to the % of, however it seems that this only allows comparison with values within the same group.

Let's say I have my data segmented by Year, then Year & Month.

If I want to compare February 2024 with February 2023, it seems to be impossible. In the pivot table, they are located in different groups (2023 / 2024), so comparing by sum, using % of, seems to only allow me comparison with next/previous row, or first/last row in each respective year.

How can I instead compare not with the previous value, but with the previous groups value?

Here is a breakdown of what I have selected in the pivot table...

Column
Sales Channel

Rows
Date (year)
Date (Mon&Year)

Data (as column)
Total (sum)
Total (sum % of difference from previous value, date (Mon&Year)

This would compare November 2022 with October 2022, and so forth. How can I compare November 2022 with November 2021?

Thanks!