Separation of categories

Hello everyone. Tell me please.
I have a few sheets:
Country
Cities
Tours in these cities
Tour Categories
When we add a new tour we indicate: country, city, category and everything else.
The question is, deduce the CATEGORY of tours in a certain city of a certain country, but in one category there can be several tours from other countries and cities! How to make a separation so that in a certain country and city there are categories of tours only from these countries and cities?
That is, when visiting a certain country or city, we could find a tour by category in this country.

Can you check if your solution can be found here?

My category sheet does not intersect with countries and cities. Only with tours. That’s why I didn’t manage to connect the conclusion of the categories of tours in a particular city or country.

Can you copy out a part of your data so I can work on it?