Think of it as a magnified Hey, It's That Voice!. Full circle portraying is where two or more characters have officially been portrayed by the same actor/actress in more than one occasion.
However, this might not count if both/all characters are from the same series. For instance, Animal and Bunsen were both voiced by Howie Mandel in the first two seasons of Muppet Babies, but they were voiced by [...] [tvtropes.org]