What kind of pickups are you using?
I was assuming you had four-conductor humbuckers. That means four color-coated wires and one bare wire. The bare wire always goes to ground. The color codes vary by manufacturer.
A four-conductor humbucker can be viewed as two single coil pickups stacked on top of each other, and there are a few different ways to wire it up. Wiring a humbucker in series is the 'traditional' way to do it. It is done by connecting two wires together, which makes the two coils run
in series; that means they act like a single pickup, working together.
For DiMarzio and Seymour Duncan, here's how you achieve that:
Now, as you see, you have two wires left over. The positive wire goes to the pickup switch, the negative wire goes to ground (along with the bare wire). The next step would be to follow the diagram you posted, acting like each humbucker is a single coil (a single positive lead, a single negative).
The other common way to wire humbuckers is to wire them in parallel. That means the two pickups have an individual output - they're working as two single coils stacked on top of each other.
That's what your diagram will do for the pickups - position 2 will be neck/bridge pups in parallel (two distinct pickups giving their output at the same time), position 4 will be neck/bridge in series (the two pickups are acting as essentially one giant pickup).