Stray dogs, parking tickets, marriages, deaths, garbage collection, housing policy, climate change, civil rights: all these matters and more figure in Frederick Wiseman’s latest documentary, an expansive look at the mundane and consequential business of city government in Boston. The film follows Democratic Mayor Marty Walsh, an affable Irish American with a spectacularly old-school accent, as he travels from conference rooms and church basements to Fenway Park and Faneuil Hall, regaling and exhorting citizens in the course of his executive duties. But it also devotes significant screen time to the labor of low-profile municipal employees, and to community meetings where ordinary people hash out local issues, doing the basic work of democracy. In his typically measured yet incisive style, Wiseman turns a study of bureaucratic process into a paean to public service and civic discourse. He said in a recent interview, “I didn’t set out to make an anti-Trump film. But it becomes an anti-Trump film because the mayor and the people who work for City Hall in Boston . . . care and believe in the democratic process and democratic norms. . . . The film represents everything that [Trump] doesn’t stand for.”