Is it possible to set up a custom taxonomy to behave in the way highlighted below. I am sure there is a word for this type of relationship/taxonomy but I can't remember it!
Say I have a CPT called People. I could use taxonomies to categorise different locations, for example a birth place and a current place for each Person. I would like to identify the country and the city.
I could set up a Custom Taxonomy. And have the countries as Parents and the cities as children. But this means someone could select a country of United Kingdom, but also a city like Paris.
Is there any way to stop this happening? So only Children under a selected Parent can be selected?