In his brilliant and thought provoking book, Deep Exegesis, Peter Leithart writes (167):
“In a book happily back in print, John Breck argues that chiasms are not ‘balanced structures, but instead are dynamic literary devices. He suggests that chiasms should be read ‘helically,’ moving not just from A to B to C to B’ and so on, but from A to A’, B to B’, C to C’, and so on. Read in this way, the text has a centripetal pull toward the central section. The corresponding sections, Breck argues, are related in the same ways that the strophes of a verse of Hebrew poetry are related. He says there is a ‘what’s more’ relationship between the corresponding lines: A and, what is more, A’.”
[the Breck book to which Leithart refers is The Shape of Biblical Language: Chiasmus in the Scriptures and Beyond]
This idea of reading a chiasm “helically” (from “helical: of or shaped like a helix; spiral”) is exactly right.
I have argued that chiastic structures function this way across the books of Revelation and Daniel, and in my forthcoming book on the theology of Daniel, I suggest that Daniel’s chiastic structure influenced the choices John made in structuring Revelation chiastically.
This helical function can also be seen in the chiastic structure of 2 Samuel 21–24 (see GGSTJ, 174–75) and is likely at work anywhere you find a chiasm in the Bible.