Key Binding and Function to Jump to Emacs Completions Buffer

Updated with a second solution. Both are useful. The new one is simpler.

I have recently disabled Ivy/Counsel/Swiper in my Emacs setup¹.

One of the first things that I experienced, after disabling Ivy & friends, was a new interaction mode with completions.

When trying to complete something in the minibuffer, completion candidates are displayed in the *Completions* buffer which is conveniently displayed right above the minibuffer.

What confused me about this behavior was the need to use the mouse to move to this buffer. Using other-window (C-x o) wasn’t working as it moved the point to the top buffer.