This film is all about unfinished business. In 1989, documentarian Christine Choy started filming the exiled Chinese student leaders who were trying to continue their movement in America, shortly after the Tiananmen Square Massacre. Since she had not been there in the Square, she did not feel a close connection to her subjects, so when she ran out of money, she simply dropped the project. She also assumed the world would force the Communist government to come to some sort of understanding with the student protesters. Obviously, the campaign for democratic reform in China remains just as unfinished her film, if not more so, since now some of her footage will finally be seen by audiences. Decades later, Choy reconnects with three of the most prominent activists she nearly documented in Violet Columbus and Ben Klein’s “The Exiles,” which premiered during the 2022 Sundance Film Festival. Choy is best-known for …