The idea is that when considering a decision we might conect with parallel selfs from different timelines where different outcomes of the decision have been experienced already. This then can inform our decision.
This theory describes quite well how I perceive this process: You load up on knowledge, but then immerse into something much deeper, visualizing/feeling different outcomes and suddenly you now which way to go.
If this process can actually bring something really new, or is simply another predetermined path, maybe is another question. Which also is widely discussed in the book mentioned.
In general my experience is that no decision ever is the same. Being rooted in arts I'd say people try really hard to arrive at recipies that produce repeatable art. But it never works, most of the time it's a dead piece of shit ;)