Filter from unrelated sheets

I have a sheet with country and countrycodes and other sheet which have countrycodes (comma separated) to filter based on country. For now there is no relation between these tables. I want a filter on different pages based on country so i will have dropdown control from Country Sheet. How can i use the selected value to filter on different pages.

My App is regarding Products, Offers, Deals.

Just adding how my countrycode column looks like. This is in all sheets like Coupons, Products, Stores.
The second screenshot is the sheet containing the country names and the countrycode.

I have different screens in the app as Coupons, Offers, Products, Stores and want a filter on each screen based on country.
I tried few things but couldn’t make it work.

Ideally what I would do is create a sheet that will hold a user specific value from a choice component. You can build the choice component based on the sheet that has the country and countrycodes. You can display the country name, but save the code to the sheet. Then in your sheets with just the country code, it would be better to set them up in array columns (Code 1, Code 2, Code 3, etc.). Each column will hold only one country code, but will be seen as an array of ‘Code’ in Glide. You can set a relation from the user specific column set by the choice component to the Code array column in the other sheet.

I had that in mind but i can have countrycode as 10, 20 or may be 100. In that case sheet will be entirely cluttered as well. Is there any better approach?