No, I don't have a note of the cables.
Give that family friend a slap.
With the 2 sets of cables disconnected in the picture, none of the lights downstairs will work as it breaks the loop.
If none of them work that means that it must be the first light on the circuit.
It also means that there's a cable missing - the one that runs to the switch. What you see there could be the end of the circuit, and the switch cable, but in that case disconnecting them wouldn't stop anything else from working.
Or maybe it is the end of the circuit and the switch cable, and whatever has stopped the other lights from working is unrelated to these cables being disconnected.
Between the 2 sets of wires there are 3 live, 2 earth, and 1 neutral,
How have you established that?
so I would guess that you connect a live to a live and an earth to an earth between the 2 sets of cables. This would leave a live and a neutral to connect up to a light fitting in the living room.
It would also leave the lighting loop without a neutral, which would be a bit of a drawback....
But that's a guess, which is why I need your help
You need to stop guessing.
You need to learn how lighting circuits work.
//www.diynot.com/wiki/electrics:lighting
You need to see if there's another cable at that location.
You need to get a multimeter.
Or, you need to do none of the above and get an electrician.