Where does “одноплемінник” come from?

одноплемінник (Ukrainian) comes from Russian одно-, from Russian оди́н, from Old East Slavic оди́нъ, from Proto-Slavic edìnъ, from Proto-Balto-Slavic edīˀnas, from Proto-Balto-Slavic aiˀnas, from Proto-Indo-European óynos — one; single.

одноплемінник (Ukrainian): fellow tribesman