Ok, I actually had a bit of trouble with this, personally, because it's difficult, mostly, to fit around the Belly of the Whale (Ordeal/Climax/Final Battle),* which is supposed to come directly after the crossing of the first threshold, and a bit of the Return sub-steps. If you change those a bit, and move it instead after the initiation, and I think it makes a lot more sense. The Return and the flight are technically supposed to come after the Atonement with Father,** etc, but really, this does make a lot of sense if you tweak the order a bit.*Also, one random thing: I came across another step I hadn't seen before, right before the Belly of the Whale, called Approach to the Inmost Cave, in which the hero pauses before entering the ordeal, typically having second thoughts and hesitating, or going though a moral conflict/struggle of some sort. This would obviously be Marius' "would my father approve of me entering" fight with himself outside the barricades, and strengthens the idea that the steps are all there, just that Ol' Vic took them out of order. ** So, I'm a bit unsure about this step, as there really is a literal reconciliation with a father figure, in this case the grandfather, but it comes at the end of the story, and the Atonement with Father is supposed to be, at least in the traditional monomyth, the "center-point" of the journey, where the hero confronts whatever holds ultimate power in his life. I guess, maybe, it's possible to play around with the idea of this literally being Colonel Pontmercy, as well, because though the "atonement" would have been after his death, there were still all these "oh-no-what-would-my-father-say-about-this" panic attacks and such. Yet, the step still seems to reflect Gillenormand, especially in this quote: "It is in this ordeal that the hero may derive hope and assurance from the helpful female figure [Cosette], by whose magic (pollen charms or power of intercession) he is protected through all the frightening experiences of the father's ego-shattering initiation. For if it is impossible to trust the terrifying father-face, then one's faith must be centered elsewhere; and with that reliance for support, one endures the crisis." It was only when Gillenormand told him he could marry Cosette that he really believed that his acceptance was real. However, then, the reconciliation comes about as quickly as Campbell says: "He beholds the face of the father, understands—and the two are atoned." So I guess, what I'm saying is that this step is debatable because it's not used the traditional way, and yet it's obviously there in some form. Sorry for the ramble.
So, at the end of the initiation (and if you insert the Belly of the Whale here, instead, and make that the barricades) is the Apotheosis, the last step before the Return here, where the hero "experiences death." This would be the period of unconsciousness, especially before the sewers, but also, even perhaps a bit of the consciousness directly before, as well, as you remember Hugo repeatedly described him as "looking out of a tomb," etc, and not being fully alive. He even originally went to the barricades to die, so I suppose perhaps he considered himself dead while yet living.
Then, if you move the Ultimate Boon and Refusal of the Return steps, the Magic Flight and Rescue From WIthout (both part of the Return stage) would be next. The former usually signifies an escape, often a chase scene, in this case from the barricades and Javert, and the latter represents literally the returning to home, the ending of the adventure, where the hero is brought back to the starting place by someone else because he is too weak to do it himself; in this case, Jean Valjean.
Then comes the Crossing of the Return Threshold, where the hero must "return to the world and accept it as real." I think for Pontmercy, this would figure in both with steps Refusal of the Return and Atonement With Father, because once he's back in his grandfather's house and conscious, he thinks that Gillenormand's doting attitude is all a trick, and refuses to accept it as reality. It's once he does, and actually says the words "grandfather," (which perhaps therefore adds the reconciliation as a simultaneous step) that he's actually reentered his grandfather's house.
Then comes Master of Two Worlds and Freedom to Live, in which he adapts himself to the world he's returned to, as well as maintains a connection with the old world, I believe, and passes through both in a sense. So, maybe because he's brought Cosette with him to his new world, that could sort of make sense, especially because she figures in as part of the reward, which is always part of the Return, and is supposed to give ultimate happiness to the hero. Also here, though, we have to find a place for the Ultimate Boon, the "achievement of the goal or quest" that benefits both the hero, and usually those around him as well. I guess it's a bit of a difficult question, but personally, at least, I thought of the boon as being Marius finding his identity and his place in the world, and taking it up while also taking care of Cosette, bringing peace to a family, and thus, fulfilling the dreams of Jean Valjean, Fantine, Colonel Pontmercy, and even perhaps Gillenormand. But that's slightly hard to defend, admittedly.
Thus, I would say the return is all the way from the end of the barricades to the end of the book: beginning with a literal, physical return, then a mental acceptance of it, and then finally a mental and moral understanding of his journey and Jean Valjean himself.
Sorry, that was long and ramble-y.