Sterlin Harjo and Taika Waititi — the co-creators of “Reservation Dogs” — met in the mid-aughts, and though Harjo is from Oklahoma and Waititi grew up in New Zealand, they immediately bonded over their shared experiences as Indigenous filmmakers. As Waititi’s star rose, the two remained friends, but “I never talked to him about work,” Harjo said. “I mean, enough people I think are trying to get stuff from Taika, so we just kept it as friendship.”