"Notice to all users" goes nowhere in bp_corporate

Hi, there is a check box in the Buddypress that lets me (as admin) send a notice to all users. But in the Corporate theme, there is nowhere for this to show up. The messages just disappear.

In the BP-Default theme, they show up in the sidebar for logged-in users.

In this thread someone proposes a code to add to the sidebar to make the Notice To All Users show up. https://premium.wpmudev.org/forums/topic/this-is-a-notice-to-all-users-check-box-doesnt-work-for-private-messages

I don't really know where to put this code. Can anyone tell me exactly what file, what directory, what part of the file? I'm willing to learn but stumbling around in the dark, currently.