How to setup Coordinator network with Xbee Pro 868 (XBP08-DPSIT-024)?


I am a newbie in the xbee world and would appreciate some help to get started quicker.
I have 3 Xbee Pro 868 (XBP08-DPSIT-024) modules and I want them to work together in the following way:
There is xBee1 who is the master (i presume the Coordinator) and two xBees, xBee2 and xBee3 (bot of them are End Devices) . xBee1 sends data (query) to xBee2 and xBee3 and xBee2 and xBee3 than send data back (if there will be something to send - Response).
I have read the datasheet of the XBP08-DPSIT-024, connected the xBee to X-CTU now I could use some help to get the communication up and running.
If I could get some pointers, what parameters have to be configured so that modules would communicate with each other.

Thanks in advance,