Cao Hamburger always knew about his grandparents’ pioneering work in São Paolo’s Jewish community. And now the Brazilian filmmaker has made his own substantial contribution — with a pen and a camera.

“The Year My Parents Went on Vacation,” set during Brazil’s military dictatorship and amid the frenzy of the 1970 World Cup, is a bittersweet story of a 12-year-old boy at loose ends after his political parents go into hiding. Left on the stoop of his Jewish grandfather’s apartment building and soon handed a sad surprise, Mauro comes to rely on the kindness of the strangers in the mixed but mostly Jewish São Paolo neighborhood.

“I think this film was my late bar mitzvah, somehow,” Hamburger says. “I always had contact with the culture, but making this film I could [better] investigate and understand this part of my roots.”

“The Year My Parents Went on Vacation” had its local premiere last fall in the Latino Film Festival, and made the shortlist of 15 titles for the Academy Award for best foreign language film. The movie opens in the Bay Area on Feb. 22.

The film began to sprout in Hamburger’s head several years ago when he was working in London.

“I was alone, my family wasn’t with me, and I was in this exile situation,” the tall, 45-year-old director recalls during a recent interview in a San Francisco hotel. “Alone in a different country, with different people, and realizing how, actually, I like to be the foreign guy. You see a different way; your sight is more accurate. You feel more sensitive somehow. I don’t know why, but I was very interested in understanding my roots.”

Hamburger’s grandparents emigrated from Germany in 1936, when his father was 2. His grandmother co-founded a huge orphanage for Jewish children in São Paolo that is still in existence (although now it’s dedicated to poor children), and his grandfather co-founded a major Jewish community center.

“My father was raised as a Jewish guy, but he turned to be a scientist first of all,” Hamburger says with a smile, turning to the translator to clarify a word. “They have their own God.” His father and his mother, a non-Jew, met at university and both became physicists. Hamburger’s awareness of Jewish culture came from his grandmother.

But this was decades ago. So Hamburger spent three years researching the Jewish community of São Paolo and Jewish culture. He took a Kabbalah course and read countless works of literature. He cites Amos Oz’s Israel-set memoir, “A Tale of Love and Darkness,” as a key inspiration in making the film.

Hamburger brought in a Jewish writing partner who grew up in the neighborhood where “The Year My Parents Went on Vacation” takes place. The director cast all the children, as well as the neighbors in Mauro’s building, from the local Jewish community.

For the key role of Shlomo, Mauro’s grandfather’s next-door neighbor and a religious Jew in his 70s with no clue how to connect with an adolescent boy, Hamburger went further afield. The search took him all the way to Recife, the site of the first Jewish synagogue built in the Americas and the birthplace of the first Jews to settle in New Amsterdam.

There he found Germano Haiut, a successful owner of several clothing shops, a leader of the Jewish community and a gregarious fellow with a half-dozen grandchildren. So Haiut would understand how to be alone, Hamburger got him to agree to live by himself in an apartment in São Paolo for 40 days during rehearsal and production.

“The Year My Parents Went on Vacation” was a success in Brazil, Hamburger reports. But that was almost a bonus.

“I think it really was my rite of passage,” he confides. “Something changed inside me about understanding Jewish community.”

“The Year My Parents Went on Vacation” opens Feb. 22 at the Sundance Cinemas Kabuki in San Francisco and the Rialto Elmwood in Berkeley.