Switching between windows of one application in multiple spaces I know you can use command + ` to switch between windows in one program in one space.

But this is only in the one space, if you have other windows from the same App in different spaces ... it won't switch to that space.
There is a shortcut to do this, though it doesn't cycle between windows; it only allows you to choose one. But it will switch to it regardless of which space it's on. It's a convenient way to access App Exposé for any app.

Press Cmd+Tab to open the application switcher. When the application whose window you seek is selected, press 1. You can then select a window by typing its title, or with the arrow keys.