Other How-To 1: Setting up Local Screen Multiplayer
Wasn’t aware of how to set this up originally, so thought it’d be a fun quick tip for those who don’t know! 
This is just “how to get started.” I didn’t use the other screen or multiple controllers here.
In your Level Blueprint add a “Create Player” Node.
Add up to four of these for split-screen. You’ll need to specify a controller ID for each though. Using the same ID will ignore this node.
If you want to adjust the Horizontal/Vertical nature of the layout go to the Project Settings > Maps & Modes > Local Multiplayer
Final Result for three-player horizontal split-screen:
