Code folding: Expand/Collapse All only on selected text

Is there a way to do code folding on selected text so that the text is all folded (or reversing to unfold)? I've tried highlighting it then both forms of folding but no luck. For example, it only unfolds the first fold.

I basically want the equivalent of Expand All & Collapse All applied only to selected text. Would this be an enhancement?

Thanks,
Jon