Complex sentence: From 1945-1949, Oestreich was "Hauptschulrat" in Berlin-Zehlendorf, from 1949 to 1950 in the "Hauptschulamt" of the Magistrat of Groß-Berlin Dezernent for higher education.
Split into simpler sentences: From 1945-1949, Oestreich was "Hauptschulrat" in Berlin-Zehlendorf. From 1949 to 1950 he worked in the "Hauptschulamt" of the Magistrat of Groß-Berlin Dezernent for higher education.