OK, looking at pics courtesy of MacFixIt,
The connection runs from the main logic board then into the camera board and then thru the camera to the bluetooth board.
Ground & 5v must be common to the bluetooth board and camera board.
Looking at the bluetooth board (which is a blue board in all the pics I've seen) there seems to be a mounting hole with a silver circle around it (I'll take that as ground).
Also note that those blue (or green) wires are shield cables (like tiny coax cables) - but whilst the shields seem to be soldered together, they don't appear to be connected thru to the camera board as a ground.
The two red wires I'll take as GND and +5V since looking at the end of the cable, the traces on the connector PCB are thicker.
This leaves 6 signal wires. 4 will be USB+ and USB- (one for the camera and one for the bluetooth board).
If you're able to trace the signals that are passed thru to the bluetooth board, you should be able to eliminate 2 or 3 signal wires, leaving 3 choices. What the 3rd signal is for, I'm not certain, but given these can be activated remotely, I'm wondering if this is to activate the camera.
Oddly, the bottom two signal traces in the attached pic seem to be soldered together (though that could be a trick of the light) - perhaps you can verify that.
If any of this is obvious, I apologize, without one here, it's a bit difficult.
EDIT: Just a guess, but the 2 unknown signal cables may be for the Ambient Light Sensor, which is passed into the main cable that connects to the Main Logic Board.
http://osxdaily.com/2010/05/22/where-is-the-ambient-light-sensor-on-a-macbook-pro/