I'm absolutely calling BS. I've never seen such a thing and wagering that you are just confused about what lanes can do what (or you're just making shit up). There are several roundabouts near me where an inside lane can turn out or go straight, but in all of those cases all lanes further out are required to turn out. The people that design traffic patterns aren't idiots, but there's no shortage of idiot drivers that can't follow even the simplest patterns.

If you want to insist, all you need to do is link to such an intersection in google maps so I can look at the aerial view. I'm honestly curious how they would paint the traffic lanes to indicate what you're describing.