Challenging relationship

Good evening community,

I have 2 middle table Region and Country, which i have used it as dropdown in my dashboard and the relationship is setup something like above

Now what happns is whn i go to the dashboard, and select a region from the dropdown, lets say CESA, it doesn't shows me the countries related to that particular region, rather it shows me all the countries listed

how do i fix this? or sync both region and country slicer?