arduino cnc with a tft ILI9486

Good day smart heads from the internet,

Just a question; how to combine arduino 2560 with tft ILI9486 shield with arduino uno with a cnc shield, is that possible?
The idea is to use buttons to select commands from an SD card to be executed by cnc .... And so, can anyone help me with a decent program?

The prepared hardware configuration:
Cnc is a UNO with cnc shield, display is a MEGA 2560 with a 3.5 'TFTLCD shield with driver ILI9486, to which the selection buttons are also connected. The additional display is new.

Just want to clarify a bit more about the selection buttons; 5 pieces and this for up and down, left and right, in the middle enter.

Thanks in advance, greetings,