Before the ultimate time of the return to Jerusalem, there are other events that will take place. The understanding of these events is also part of Nephi’s prophetic vision, one that is now many years past, yet clearly still crisply memorable. Nephi describes the coming of Jesus and his rejection by the Lord’s people.
Narrative: “Prophetic history” is informing the structure of Nephi’s discussion, but it is not a linear progression. Nephi justifies the prophecies by linking the destruction/scattering to a redemptive gathering. This gathering is temporally located in the eschatological future. However, once he sets the outline as one that requires the end to counter the beginning, he moves to intermediary events.
This is either another example of a rather rambling approach to his style, or it is an imprecise structural use of the concept of chiasm and balances, where the critical major structure is to create elemental balance. Thus the redemption must follow the destruction. The return to the concepts in the middle would therefore simply be a different structural model than the modern expectation of chronology.
The problem with using chiasm as a complete organizing principle is that the passages do not fall into a tight chiastic structure. Thus it is the idea of balance in the chiasm that would be used, not the literary device itself.