Adaptors used for both IPTV and Internet

Maybe I did not explain clearly why I think there might be a problem.
In one room, the Powerline adaptor 1 will be used to connect to an ISP socket to carry IPTV to the living room, where adaptor 2 will connect to the TV
In the second room, Adaptor 3 will be used to connect to the router and then adaptor 4 will be useed freely around the house.

So given that adaptor 1 is carrying an IPTV stream and adaptor 3 is carrying L2TP-based Internet access - I do not see how adaptor 2 should KNOW that is connected specifically to adaptor 1 (for IPTV) instead of adaptor 3 (for Internet access)?
The same goes for adaptor 4: how will it know that it should only look to adaptor 3 for Internet access and not to adaptor 1 for IPTV stream?

It is almost as if 1-2 need to be paired permanently; then 3 and 4 need to be paired permanently.

Or does your answer mean that adaptors are somehow "clever enough" to know where to look at?

Thanks for your patience and time
LT