The master sends to the bus. The slave devices accept only command/data addressed to it. The bus dissipates the signal through the terminating resistors at the ends of the bus to stop reflected signals. [edit] a "monitor" device will accept all data and commands, but will not perform the command
You can use the receive module as a bus monitor. You can use the IDE or in my case I use Putty, a terminal program good on most home computers. I use Linux and I can have as many IDEs open as I like, several together or in different work spaces. You can build the monitor for less then $10 us carefully shopping your favorite china supplier. It will take 7 jumpers, a china Nano a MCP2515 module and a USB cable. The USB supplies the power.