Can-bus communication protocol

Hi
I am just trying to do CAN-bus communication protocol with Arduino. I want to use two transmission nodes (Transmitter1, Transmitter2) and one receiver node. The receiver should ask which transmitter data will be received. For example, the receiver asks Transmitter1 about the data and at other times asks the Transmitter2 about the data.

So, I just want help or some notes that help me in my work.