Going through some material I recently came across this structural analysis of the Gospel of Matthew as a whole. It is done by H.C. van Zyl - a South African theologian who published his article in Neotestamentica (Van Zyl, H C. “STRUCTURAL ANALYSIS OF MATTHEW 18.” Neotestamentica, vol. 16, 1982, pp. 35–55. JSTOR, www.jstor.org/stable/43049277. Accessed 10 Sept. 2020.). 

To provide a macrocontext for his understanding of Mt. 18 his presents the work of Lohr, Ellis and Vorster who believe that Matthew composed his Gospel following way:   

A. 1-4, Narrative: birth and beginnings 

 B. 5-7, discourse: beatitudes, entry into the kingdom

  C. 8-9, narrative: authority and invitation 

   D. 10, discourse: mission 

    E. 11-12, narrative: rejection by this generation

     F. 13, discourse: parables of the kingdom 

    E'. 14-17, narrative: recognition by disciples

   D'. 18, discourse: church order

  C'. 19-22, narrative: authority and invitation

 B'. 23-25, discourse: "woe to" sayings, coming of the kingdom

A'. 26-28, narrative: death and "rebirth" (resurrection)

I believe it is very helpful tool that can help Bible students to grasp the plot and the flow of the Gospel.