Complex sentence: Bradford Young and Joi McMillon became the first African-Americans to be nominated for Best Cinematography and Best Editing categories, respectively, while Ava DuVernay was the first African-American to received an Oscar nomination for Best Documentary Feature.
Split into simpler sentences: Bradford Young and Joi McMillon became first African-Americans to be nominated for Best Cinematography and Best Editing categories, respectively. While Ava DuVernay was the first African-American to received an Oscar nomination for Best Documentary Feature.