Even if you could running a single repeater is going to cause you large degradation in the performance, running 2 would cause even more interfering radio signals.
What you want to do is not even supported using ethernet cable on consumer grade routers. You have 2 different networks and you would need vlan support to get this to work even on a wired network.
It is possible to do this using a different kind of "repeater". What it actually does is build a point to point bridge connection back to the main router that support vlan tags. It then using completely different radios than used for the bridge sets up the new SSID ...pretty much a bridge connected back to back with a AP but supporting vlans.
So unless you are willing to build your own using third party firmware or buy a solution sold to enterprise level customers the answer will be it can't be done.