Multiseat on Mac OS?
There are no native multi-seat solutions for current macOS that allows multiple, simultaneous users on the same Mac each with their own screen, keyboard and mouse.

You can create a multi-seat solution by running Windows or Linux on the Mac instead of macOS.

In theory you could also run for example a native Linux and virtualise several macOS instances to provide multi-seat usage of macOS on the Mac. In practice, you'll have licensing worries amongst other things.