The first part of this definition involves an initial statement or opinion. The second part refers to another statement or opinion at least somewhat related to the initial statement or opinion. The word "nother" implies a mix of the words other and another, and the word "other" indicates a derivative. The word "shit" in the phrase refers to something bad, but can also be good.
(1) Yea we still talk, she still has hangups on her ex, but thats some nother other shit.
(2) He is a douchebag, but we still fuck, but that some whoooole nother other shit.