How to have my application window appear in both my laptop screen and monitor screen?

Hopefully I can word my question properly since Google doesn't understand me.

I have a second monitor hooked up to my MBP and I've arranged the laptop screen to be below the monitor (see attached photo).

What I need is to have my application window appear in both the monitor and laptop screen but split between the two. In my case, what's happening is when I drag my windows around, the top half of the window is in the monitor but the bottom half doesn't appear in the laptop screen. I have seen other colleagues around work where the respective halves appear in both the monitor and laptop screen.

What setting is needed to make the full application window appear in both the monitor and the laptop screen?

Solution 1:

You need to change the [] Displays have separate Spaces preference, by unchecking it in System Preferences > Mission Control.

Note that with this unchecked, you'll not be able to use apps in Split View.

_{Note that you'll need to log out/in for the change to take effect.}