In 1928, he was taught by Otto Falckenberg, the director of the Munich Kammerspiele, in acting and directing.
[citation needed] In 1936, Liebeneiner became a member of the Prussian State Theater (Preußisches Staatstheater) in Berlin and in 1938, he became artistic director of the German Film Academy Babelsberg (Deutsche Filmakademie Babelsberg).
In 1941, he directed the film Ich klage an (I accuse) in cooperation with the Ministry of Public Enlightenment and Propaganda.
In 1947, Liebeneiner directed the debut of Wolfgang Borchert's play Draußen vor der Tür (The Man Outside) in the Hamburg Kammerspiele.
He died on 28 November 1987, aged 82, in Vienna after a long illness.