How to Batch Export buttons?

Hi, I just upgraded to MGP 1.7.7 from 1.7.4.
In the 1.7.4 changelog, under the new features, is “Export multiple selected buttons in one operation”. I can’t find a way to do this because if I select more than one button I can’t go to the button edit page where I’m able to export a single button; so what’s the way to export multiple buttons at once?