You won't - the guide is a guide to the Wiring Regulations and/or Building Regulations (depending which one you mean) - not a design guide or a guide to domestic lighting circuit topologies.
This is from the Electrician's Guide to the Building Regs - looks like a diagram to me, just not what I needed. But I take your point about it not being a design guide.
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I really do think you should do some learning
I have undertaken a significant amount of reading and asked questions and as a result identified a number of safety problems due to the age of the wiring in my house. In this case I was unsure how to proceed so asked a very specific question. Your links were unrelated to the point, and appeared patronising. However, thank you for clarifying your intent.
In respect of the Part P (semantics of qualifications aside) my understanding from training companies, eg. Builder Training Centre - it is possible to reach the level of being able to apply for self certification status - following as you say, the C&G parts - in all about 10 days. Presumably, this would require some pre-read and practice.
At a cost of about £1800, I reckon that is about one-third of the cost I would be quoted for a re-wire, so if I could self-certify I potentially save £3500 and gain a skill. I have made a guess as to a possible quote for a re-wire, so these figures may be wrong. Also, I want to re-wire my house, not go into business as an electrician.
What I would find helpful is an electrician who would visit, advise and subsequently inspect - at a cost that reflects the input. ie. a generous hourly / day rate that compensates for the lost opportunity (business) cost.
I guess like many on the forum, I do not want to pay someone else to knock holes out for boxes, chase walls or run the wires, but I would pay a good rate for advice on how to do it. And teach me how to wire two lights!!!
The law says I am allowed to do this, but I believe (perhaps incorrectly) that I would not persuade a qualified person to work with me in this way.
Of course, this could be applied to other roles, such as plumbing, etc. where mistakes might be less dangerous!
I apologise for the length of this response, but you have been kind enough to provide a comprehensive follow-up, thank you.