I have a panel where a user selects a camera to view from a location so they can load images from that camera. They can only load images from one camera and one location. Because of this I used radio buttons; only one valid entry per location. But the individual groups of radio buttons are also mutually exclusive.
An example is below. Camera 1 from the first location is selected. If I selected Camera 2 from the first location, the camera 1 button pops out. It also pops out if I chose a camera from another location.
I physically grouped the buttons to suggest connectivity, but I don't know how I would or if I should indicate the separate groups are also mutually exclusive. It's quite apparent from using the interface though, as the buttons will visually pop out if you chose another option.