Five nominees are in the running to succeed Bishop M. Thomas Shaw, who has led the Episcopal Diocese of Massachusetts for almost two decades and plans to retire in September. The candidates — announced Wednesday by the diocesan Standing Committee, which advises the bishop — include two local priests, as well as a third with ties to Massachusetts. The nominees, who range in age from 49 to 61, include one African-American candidate and one woman. Episcopalians will have a chance to get to know the nominees in mid-March, when meet-and-greet sessions will be held at a variety of parishes in advance of the April 5 election.