Complex sentence: The Piet Zwart Institute is the center for postgraduate study and research of the Willem de Kooning Academy, Rotterdam's art school which in turn is a part of Hogeschool Rotterdam, a university of applied sciences.
Split into simpler sentences: The Piet Zwart Institute is the center for postgraduate study and research of the Willem de Kooning Academy, Rotterdam's art school. The de Kooning Academy is a part of Hogeschool Rotterdam, a university of applied sciences.