This map reflects ZARAHEMLA and NEPHI at the time of Alma 22. It shows the southern border lands of ZARAHEMLA, the narrow strip of wilderness which separated ZARAHEMLA and NEPHI, the wildernesses along the west sea and east sea coasts that were inhabited by the more idle part of the Lamanites, and the lands in NEPHI that have been identified. The blue lands are those which had large scale conversions as the result of the missionary efforts of Mosiah's sons. The place of Mormon is grayed out because the text is silent as to its population and reaction to the missionaries.
The land of Jerusalem included "a great city, which was called Jerusalem," and which was built by the Amalekites and Amulonites (Alma 21:1-2). Jerusalem joined "the borders of Mormon" (Alma 21:1). We find out in 3 Nephi 9:7 that the city Jerusalem was destroyed at the time of Christ's death: "and the city of Jerusalem and the inhabitants thereof; and waters have I caused to come up in the stead thereof." Mormon does not provide any information about Jerusalem's fate after this destruction, whether it remained covered by water, and he does not name it as one of the cities that was rebuilt.
Aaron went to the city Jerusalem to preach to the people, but met with such resistance from the Amalekites that he left the city and went "over to a village which was called Ani-Anti, and there he found Muloki preaching the word" (Alma 21:1-11). Failing there, the two missionaries went "over into the land of Middoni" (Alma 21:12). The relationship of Jerusalem to Mormon, and of Middoni to Jerusalem allows us to locate these two new lands.
Ishmael was the land governed by King Lamoni. After Lamoni's conversion, he wanted to bring Ammon to meet his father, the King of all the Lamanites, who lived in the city of Nephi. Ammon, however, received instructions from the Lord to not go to see the King, because his life would be in danger, but to go instead to Middoni to free his brethren who were in prison. On the way to Middoni, Ammon and Lamoni encountered Lamoni's father, who was on his way to see Lamoni in Ishmael. Mormon does not specify exactly where this encounter took place, but it did not occur in Middoni or Ishmael, but somewhere in between: "Now the father of Lamoni commanded him that he should slay Ammon with the sword. And he also commanded him that he should not go to the land of Middoni, but that he should return with him to the land of Ishmael (Alma 20:14, emphasis added). Since Lamoni's father was on his way from Nephi to Ishmael, Nephi lies between Middoni and Ishmael, and the chance meeting took place in Nephi.
However, this seems inconsistent with the command Ammon received in Alma 20:2: "And the voice of the Lord came to Ammon, saying: Thou shalt not go up to the land of Nephi, for behold, the King will seek thy life; but thou shalt go to the land of Middoni; for behold, thy brother Aaron, and also Muloki and Ammah are in prison." Why would the Lord tell Ammon not to go up to the land of Nephi if they have to go through Nephi to get to Middoni? If I live in California and I planned to go to Oregon, but someone wanted me to go to Washington, they would say, don't go to Oregon, go to Washington, knowing full well that I would go through Oregon to get to Washington. And, if my placement on the map is correct, Ammon and Lamoni could go through Nephi but easily avoid the city of Nephi, where the King lived. The road from the city of Ishmael to Middoni most likely connected with a road that led to the city of Nephi, the combination of which would have been the main route from the city of Nephi to the city of Ishmael. It was only by a chance meeting the the King met Ammon and Lamoni on their way to Middoni.
Very little information is provided for Midian. It is mentioned only in Alma 24:5. When the Lamanites prepared to attack the converts, Ammon met with his brethren in Midian, "and from thence they came to the land of Ishmael" for the purpose of holding a council to discuss how the converts should defend themselves. Since King Anti-Nephi-Lehi had already gathered the people together into Nephi, and since the northern lands were not converted, but controlled by the Lamanites, it seems likely that Midian was to the south of Nephi. Although it was not specifically mentioned by Mormon as one of the lands converted, it must have at least been friendly to the converts.