Documentary filmmaker Talal Derki is Syrian, but several years ago, he fled that country and now lives in Berlin. But he wanted to know why his country had descended into chaos. So he went back to film a family of men and boys who fight for Al Qaeda. Derki presented himself as sympathetic to the cause, although he is not. He was with them in a desert compound in northern Syria for more than two years. His film is called “Of Fathers and Sons.” It won the World Cinema Grand Jury Prize at the Sundance Film Festival, and is now nominated for an Oscar.