According to Nehemiah, this part of the story tells us about the families who returned to Jerusalem after being taken far away by a king named Nebuchadnezzar. Now, they are coming back home to their own towns.
Nehemiah 7:6: These [are] the children of the province, that went up out of the captivity, of those that had been carried away, whom Nebuchadnezzar the king of Babylon had carried away, and came again to Jerusalem and to Judah, every one unto his city;
Nehemiah 7:6 lists leaders of the group differently than Ezra 2:2.
Ezra 2:2: Which came with Zerubbabel: Jeshua, Nehemiah, Seraiah, Reelaiah, Mordecai, Bilshan, Mispar, Bigvai, Rehum, Baanah. The number of the men of the people of Israel: [Seraiah: also called, Azariah] [Reelaiah: or, Raamiah] [Mispar: or, Mispereth] [Rehum: or, Nehum]