Mac with 2 monitors, how do i switch virtual desktops on one monitor only?
I am not on a My Mac at the moment, but in the Mission Control Preferences there is a setting to have the spaces work independently. Go to Preferences -> Mission Control -> Displays have separate Spaces.
To add to @markhunte, the switching of desktops seems to depend on where the focus or mouse, is. I have 2 external monitors and 3 spaces on my primary display. When I add a space to an external monitor, the key-combo of Control + <- or -> will move the space where the active app or my mouse is located.