Dependant dropdown

I have two dropdown fields that I want to be dependant but I can't figure out how.

Example Dropdown one: Country, dropdown two: Cities

A simplified version:
Table one: id, country
Table two: id, city, country_id

If I select country I want the next dropdown to load all cities with corresponding country_id.

I've tried creating an extended sql field for the second dropdown that should filter from the first but it's not.

Dependant/chained select might not be possible in Component Creator, I haven't found any information about it. I've Googled many hours on how to create a dependant dropdown in a joomla form and filter field but I'm not finding anything useful.

Anybody else having any experience with this or knows how to get dropdown fields to chain? Any ideas would be appreciated!

Yes, I figured as much. The question is how to do it manually. I'm surprised that I can't find any information anywhere on how to do it manually. Time to hire a programmer I think. Know your limits! Thanks!