I interpret that diagram to mean that the Red and Green wires are for the Neck side coil — and the Black and White wires are for the Bridge side pickup. FWIW, that is consistent with what I’ve seen from Nordstrand.
So I’ll say that you want the red and green side singled on the neck pickup and the black and white side singled on the bridge pickup — the outer coils singled. Which makes P1 the neck pickup and P2 the bridge pickup.
It’s easy to test which is which while putting it together — so’s there’s a very small penalty for getting it wrong the first time. It would only take a few minutes to put it right.
The dashed lines I’ve added are probably optional. They ground any unused wires coils on both wires. I can’t see the harm in leaving them floating but there is no downside to grounding them.
To be sure, each row is a “pole”. The common terminal in each row is connected to exactly one other terminal in its row. For each position, when selected (Series, Parallel, Single or Off), the terminals in the column under that position are connected to the common terminals to their left.
None of the rotary switches I find online include pinouts — which I find odd — but determining the pinout in order to match the diagram is a simple matter with a multimeter.