[Panamon Creel]

You would need a DPDT-CO switch to do that, Center position Aux Lights off, outer positions for Aux Lights on with High beams and Aux Lights Manually on at the other side. One pole connected to High beam light circuit, other pole with +12V supply (Aux, ignition or permanent whatever your desire ) No need for Diodes this way since the circuits are separated at the switch going to the relay

 

[Panamon Creel]

Well correction you can also do it with a SPDT-CO Switch and circuits would still be separated without diodes

 

[Panamon Creel]

Depending on the Relay you may have to add a capacitor/diode compo to the coil side to avoid relay chatter caused by the PWM on the Highbeam circuit when the engine is running.

 

[Panamon Creel]

Here a Diagram showing the circuit with capacitor&feedback blocking diode as well as a surge suppression diode across the coil.