Multiple wired remote installation

I have a Sony XA-C40 Unilink Source Selector and 3 Sony RM-X55M wired remote commanders. I wanted to know if this will work or not. I contacted Sony support about my wanting to connect 3 wired remotes on my boat so I can control my head unit from 3 different zones and they told me to get the XA-C40 to do this. I got one but in loking at the install diagram, I don't see a connection point for the 1/8 jack looking cable, on the XA-C40. The XA-C40 has a connection point for up to 3 of the BUS cables and RCA's (which I don't need in this instance). Just wanted to see if anyone is experienced with what I am trying to do. Thanks! By the way, do you know if they make a 3-way 1/8 splitter?

 

Saw that no one replied to this post. For the benefit of anyone wishing to do this same thing, I recently completed this instalation. It DID I FACT WORK! I actually got a total of 4 controllers connected to my Sony head unit. And the setup works perfectly. The XA-C40 will only accept 3 sources (in this case, remotes) so I had to piggyback two XA-C40 units. One unit connects two remotes and the second XA-C40. The second unit holds the other two remotes. The remotes are great. I now have full control of my head unit anywhere on the boat, even while I am in the water (either side and front).