The way I have understood is that this isn't something you can use but instead both source and target devices must have this built-in to make a use of it.
So, let us say source S and a AV receiver have this feature built into them. And Source S has Ethernet input for internet and has an HDMI out. So, when you connect source S to your AV receiver, receiver will be able to share the internet connection despite there isn't any Ethernet going to AV receiver.
btw, I am still reading about this and will share as soon as I get more information.