adapted from Symmetrical Design in the Book of Ruth, Stephen Bertman, Journal of Biblical Literature, Vol. 84, No. 2 (Jun., 1965), pp. 165-168. This overview fits well with the chiasms already posted. [my suggestions for understanding the types].
A. Family history (1:1-5)
B. [Jewish and Gentile widows together destitute in Bethlehem]
(1) Ties of kinship are at issue (1:8-18)
Naomi and Ruth travel and come to Bethlehem (1:19)
(2) The women of Bethlehem speak to Naomi; the afflictions received by Naomi from the LORD are spoken of; Naomi gives herself a name (1:19-21)
C. [Gentile woman shares the blessings of the inheritance of Israel]
(1) Ruth asks Naomi if she may go to the fields and tells her what she would do; Naomi bids her go (2:2)
(2) Ruth goes to the fields (2:3)
(3) Boaz asks the identity of Ruth and is told (2:4-7)
(4) Boaz asks Ruth to stay, declares her worthy of being blessed, and gives her food (2:8-14)
(5) Ruth speaks with Naomi: Ruth tells her what has happened and Naomi gives her counsel (2:18-23)
C’. [Gentile woman accepted by the royal line of Judah]
(1) Naomi bids Ruth go to the threshing-floor and tells her what she should do (3:1-5)
(2) Ruth goes to the threshing-floor (3:6)
(3) Boaz asks the identity of Ruth and is told (3:7-9)
(4) Boaz declares Ruth worthy of being blessed, asks her
to stay, and gives her food (3:10-15)
(5) Ruth speaks with Naomi: Ruth tells her what has happened and Naomi gives her counsel (3:16-18)
B’. [Jewish and Gentile widows together redeemed and blessed with royal seed]
(1) Ties of kinship are at issue (4:1-12)
[Boaz and Ruth wed and have a son (4:13)]
(2) The women of Bethlehem speak to Naomi; the blessings received by Naomi from the LORD are told of; the women of Bethlehem give Naomi’s nursling a name (4:14-17)
A’. Family history (4:18-22)
A Setting, family, death (1:1-5)
B God’s provision (1:6)
C “Make a choice” [one “no” and one “yes”] (1:7-18)
D Report (1:19-21)
E Barley harvest (1:22)
F Blessing of Boaz (2:1-4)
G Discovery of Ruth (2:5-7)
H Ruth given instructions (2:8-9)
I Establishing connections (2:10-13)
J Boaz feeds Ruth (2:14)
K Instructions on gleaning (2:15)
L “Be generous and do not rebuke her” (2:16)
K’ Gleaning and threshing (2:17)
J’ Ruth feeds Naomi (2:18)
I’ Establishing connections (2:19-23)
H’ Ruth given instructions (3:1-6)
G’ Discovery of Ruth (3:7-9)
F’ Blessing of Boaz (3:10-14)
E’ Barley harvest (3:15)
D’ Report (3:16-18)
C’ “Make a choice” [one “no” and one “yes”] (4:1-10)
B’ God’s provision (4:11-12)
A’ Birth, setting, family (4:13-22)
The point of examining a chiastic structure is to see what lies in the center, for it reveals the focal idea of the pericope. In this case, the admonition to be generous to a Moabite woman rather than rebuking her for trying to become a part of God’s people indicates the message of the inclusive direction of Judaism which developed after the Babylonian exile (in contrast to Ezra-Nehemiah).