The manual at page 25 reads:
 
"Right-clicking on it (X-Y Pad) causes random movement... ....position of the X-Y Pad is saved in the program...  ...all movements can be recorded as automation in all hosts supporting direct parameters automation"
 
I right click on it while holding down a chord, but I was not able to record anything. Does anyone know how to do that?

In X2

• Open the automation lanes in the audio or instrument track.
• Select Z3TA+ 2 > Arp Length - Osc 5 Drive > X-Y Pad X from the parameter drop down
• Add another automation lane
• Select Z3TA+ 2 > Arp Length - Osc 5 Drive > X-Y Pad Y from the parameter drop down
• Write enable both automation lanes

 
When the transport starts, the movement of the X-Y pad will be recorded into the automation lanes. Make sure to turn off the writes on the lanes when you are done. Writing automation does not need to be recorded with the MIDI but can be if you wish.

Ok, that worked. Thank you.