A longtime admirer of Bertolt Brecht, documentary maker John Walter goes behind the scenes at the Public Theater’s 2006 staging of Mother Courage and Her Children in Central Park. Meryl Streep, who starred in the production, and Tony Kushner, who supplied a new translation, discuss the play’s importance and their creative processes, yet Walter (How to Draw a Bunny) reaches past these marquee names to other engaging experts: Carl Weber, a Stanford University professor who was once Brecht’s assistant; novelist Jay Cantor; and Public Theater creative director Oskar Eustis. Rare home movies show Brecht and his happy family in Germany before they fled in 1933, and the end of his American sojourn is marked by archival footage of the playwright, a committed Marxist, testifying to the House Un-American Activities Committee in 1947. Engrossing and timely, this crackles with ideas about art, politics, religion, and the terrible costs of war. In English and subtitled German. 96 min.