Multiple Drafts, Sent, and Trash folders in "on my mac"

I have to keep Trash, Sent, and Draft folders from my Exchange account on my mac (because our mail server does dumb things if I keep them there). The Mail app in Big Sur shows all of these in "On My Mac". So, I have two Drafts, two Sents, two Trashes. This clutters my screen so that I can no longer see what I need to see (I sometimes move stuff from one folder in one account to a folder On My Mac). I can already see ALL Sents, Trashes, and Drafts in my Favorites.

How do I hide these folders in "On My Mac", so that I only have to look at them in my Favorites folder?