One of this year’s Berlinale selections has already sparked controversy as the festival comes to a close this weekend. “Dau. Natasha,” the sophomore feature from Russian director Ilya Khrzhanovskiy, is a harrowing film experiment in which the director built a vast 42,000-square-foot set in Kharkiv, Ukraine, and cast some 352,000 people to live 24 hours a day in a meticulous rendering of a Soviet science institute. Ordinary people are asked to live in full character and hold normal jobs — even if that means facing repercussions from authorities if they wander from their routine. The movie, which won a cinematography prize out of the Berlinale on Saturday, culminates in a queasy scene of sexual assault that has led a group of Russian journalists to question the ethics of including the drama at all among the competition titles. In tandem, the director is tangling in his own share of controversy over the ambitious film.