Since there's no loom for spotlights from factory it's all custom and we just gotta go back to basics.
So it works pretty much like this (so that it's legal): You flip a switch inside the cabin which enables a relay out the front. Out the front, high beam activates the relay and passes power directly from the battery to the spotlights. That's the end of the simple, now let's pull it apart.
Inside: only has to be an earth point to one side of a switch, and the other side of the switch is a single wire running out to the relay in the engine bay, preferable somewhere close to where the two spotlights are or at least between the battery and those lights. Not too far from there, anyway.
Relay: Can only turn on if pins 85 and 86 are oppositely polarised (this is important for some models, see note 1 below) and active. This means putting positive 12V to pin 85 does nothing if pin 86 is not earthed and that's where the wire coming from inside the cabin joins to. Pin 85 should connect to the HIGH BEAM wire going to one of your headlights (see note 2 below). Pin 30 should have a heavy wire connected to it and the other end has a suitable fuse (say 30A for a pair of 130W lights) and connect directly to the positive battery terminal. Pin 87 should head to both driving lights (red wire) along with a direct chassis or battery negative feed as well (black wire).
Hope that helps.
Note 1: some newer cars don't use constant positive-positive-ground on their H4 globe inputs. The only way to fire driving lights off these is to plug both pins 85 and 86 onto the HIGH/EARTH pins of the H4 globe and run the output of the relay to pin 85 on another relay, which has pin 86 connected to your earth-on switch in on your console. The output of this second relay goes to the driving lights.
Note 2: H4 socket (wire side) looks like this usually. For the globes to work it's pretty hard to wire 'em up differently anyway! This isn't from a Navara, I just found it on a site and it's not too bad.