RLS on region level

I am trying to apply RLS such that, I have an excel file with user email and region and main table containing data with region
I want to create a role such that, if one user belonging to specific user logs in should see the entire data for that region including others belonging to the same region and not only their data

 Following is the role I am trying to apply on the Main Table, however there is no impact,

I want to keep the access dynamic instead of creating role for each region.