In 2017, Bolmaro won a silver medal with Argentina's Under-17 national team at the FIBA South America Under-17 Championship in Lima, Peru. He averaged a team-high 13.8 points per game. Bolmaro also represented the Argentine Under-19 national team at the 2019 FIBA Under-19 World Cup in Heraklion, Greece, where his team finished in 11th place. He left the tournament's opening game early, with a minor strain. During the tournament, he was Argentina's leading scorer, with an average of 10.8 points per game.