Film director RaMell Ross is unapologetic about his focus on the Black South in his work. His first feature-length documentary, “Hale County This Morning, This Evening,” captures the educational experiences, the class struggles and the reverberations of Jim Crow segregation in an Alabama community, earning him an Oscar nomination in 2019. 

“Nickel Boys,” Ross’ first narrative feature, falls in line with his professional and personal mission. He and producer Joslyn Barnes adapted…