You can get a selector. That splitter cable will also work.
It will
not show an HDMI 3... Basically if you plug the splitter into HDMI 1 port in the TV, then the two sources (eg. Your bluray and your gaming console) will be played in that selection. New gaming consoles (ps3/ps4/xbox1) have built in blu ray players so I would say you can remove the blu ray player out of the system completely.
If you want to save money however, I would suggest removing the blu ray player completely, OR depending on how hard it is to get to the back of the TV or how often you play, you can just switch the HDMI cables over.
The splitter may have a switch or a button on it to select between either of the outputs though, you can't run two sources (signals) at the same time through it.
Good luck... as always PM me if you run into any issues