Re: How do I start splitscreen on PS4 PVZ GW2 Deluxe?

If you look toward the gate of the base you are in, there is a machine to the right of it (still inside the base) that lets you start split screen. The machine is further right of the Customization Booth, which is the booth with a top hat on it.

Note that split screen cannot be used for online play, but you can play all the multiplayer modes in a private session with bots using split screen.