Your current wiring will work fine and is one of many possible configurations.
When configuring your functions in the Mach4 input signals chart, you will
duplicate the settings on the line for each function that uses the same
input. Assuming that you have the Y axis assigned to Motor1, then you
would put the same entries in the Input Signal line for:
Motor 1 Home
Motor 1 ++
Motor 1 --
These lines are not near the top of the Input Signals chart and you will
need to scroll down to see them.
You would enter these settings in the respective columns for each Y axis line:
MappingEnabled green check mark (click to toggle)
Device SmartBOB USB (click in box, then select from drop down list)
Input Name Pin 11 (click in box, then select from drop down list)
Active Low red X mark (click to toggle)
Repeat the process for the X and Z axes.