keyboardspaces
My two displays (let call them A and B) have separate spaces. I can go back and forth among the spaces on the active/focussed display A. Is it possible to go back and forth among the spaces on B with keyboard shortcuts and without moving the focus to B?
I do not mean assigning keyboard shortcuts to each space, because there are more than ten spaces and plenty of maximized windows.
Go to System Preferences -> Keyboard -> Keyboard Shortcuts. Then, on the left side, select Exposé & Spaces. On the right side you will see the current keyboard shortcuts for Exposé and Spaces. If you double click on the shortcut command (literally double click ^1 for instance) you will be able to change this to whatever you want. Just do the key-combo you want to use.
So, once you double-click on the shortcut, it'll show it as editable. Then, press the keys you want the short cut to be, all at once, for instance press Apple and J at the same time, and it'll change the shortcut.
Keyboard Maestro can do this using a macro such as the following:
Best Answer
There is another question here on Ask Different that answer this question: Keyboard shorcut to switch focus between multiple displays on OS X 10.9.5 + (mavericks, el capitan, sierra)
Here's the quick summary:
There are some utilities (window managers) that allow you to assign a keyboard shortcut to the focus of a specific monitor. They are as follows (links provided):