Screen switch and orientation

In DeSmuME there is an option to change screen orientation and limit it to view just one of them. I can’t find a away to do it in RetroArch. I’ve tried to set a key for “Quick Screen Switch” but it haven’t done anything. What am I doing wrong?

As far as i know, the basic mapping for screen switching is the right stick button / R3. It worked for me out-of-the-box while using the hybrid screen setting.

Sorry to awaken an old thread - I have screen switch working but is there a way to set a hotkey to rotate? Certain games need to be held like a book and while I can go into options to do this it’s a bit of a pain!