How to split screens?

Question

linux

Hello, I ran into this problem:
When streaming a screen in Discord, I want to show only one screen.
I choose to show 1 Display but after selecting and starting the stream, it shows 1 Screen + 2 Screen, it turns out one big screen, how can I separate them so that Ubuntu understands that I have 2 different displays ?
Working on Ubuntu 20.04.2 LTS
Thanks in advance.

Answer 1

Run 2 copies of X. I won’t answer right away, I have to dig. Go ahead if you are not afraid of difficulties. But I suspect you will not solve this problem. If I'm wrong - write an article on Habré.
Otherwise - if the application can show an arbitrary part of the screen, but I have not heard of this. If you extended the desktop to two monitors, then for, let's say, the operating system, this is one space, and you need to cut it in an arbitrary place.