How to fix relationship needed error to get slicer to work

[theholychicken]

Hi,

I have two pivots:
Pivot 1: Contains the Month, Zone name, Store type, and Store ID (All in the pivot field)
Pivot 2: Contains the Month, Store type and product wise sales

I have then created a slicer on "Month" field for one pivot and connected it to the other pivot.

However, the slicer filter is not affecting any change on the 2nd pivot. I am getting the yellow box error "Relationships between tables may be needed".

Please do let me know how can I fix this.

Sincerely
Shalabh