Where does “Mitru” come from?

Mitru (Romanian) comes from Romanian Dumitru, from Old Church Slavonic Дьмитръ, from Ancient Greek Δημήτριος, from Ancient Greek Δημήτηρ, from Ancient Greek μήτηρ, from Proto-Hellenic mā́tēr, from Proto-Indo-European méh₂tēr — mother.