How to position parts relative to each other in Kicad?
The easiest way is to use the "Position Relative To" command.  On a Mac, it is ⌘-R, under Linux, it is Ctrl-R.  Or, you can access it using the right-click on a part or group.



Once you have selected this, you can choose an object for the reference



You will need to be running version 5 or higher for this function.