I've parachuted and bungee jumped but rock climbing is a whole 'nother thing.
I didn't mind being called an idiot, but when it comes to attacking my family, that's a whole 'nother ballgame.
When you're dealing with children, that's a whole nother issue.
He didn't come home last night, but that’s a whole 'nother story. 他昨晚没有回家,但这完全是另一回事。
That's a topic for a whole nother post.