This term refers to a group with a similar ethnic or cultural background, who may or may not live in a common geographic area.

I believe the answer is: nations

To be considered a nation, the area had to fulfil 3 criteria. It has to had a border, a government, and group of citizens. Even if the members of the nations is somehow had to live in another nation's territory, they can still maintain their citizenship as long as they follow the regulations created by their government.