Weird "Filter" dropdown menu on users (as a server mod) ???

Just a few minutes ago I was casually reading some messages in my discord server and I was hovering around with my mouse as I like to do, until I accidentally pressed some buttons on my mouse while hovering over someone's pfp and because I'm the owner of the server the mod dropdown menu popped up.
But at the bottom of the menu there was a "Filter" option which opened another dropdown menu with 3 other options - one of which was called "Block IP" or something similar. The description of the option was something like "Block messages", etc...
I'm guessing it was some kind of automod but this is my first time seeing it and when I closed the menu I couldn't find the option again. Anyone know what it is?