Sort Month Year Slicer Descending

Hi, Anonymous 

As you said, you have a MonthReverse Column present, so I assumed some data for testing:

You must make sure that the type of your MonthReverse Column is whole number:

Then drag the Month field into Slicer's Fields panel:

Then click on the Month field, find the Sort by column at the top and select the MonthReverse Column:

This gives you the freedom to choose whether your Month column is ascending or descending based on the MonthReverse Column:

I've attached the pbix file for this little example below, hope it helps.

I hope my suggestions give you good ideas, if you have any more questions, please clarify in a follow-up reply.
Best Regards,
Fen Ling,
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