Complex sentence: Jonas Vaitkus has mentored a number of actors and directors, including director Oskaras Koršunovas and actress Ingeborga Dapkūnaitė, both of whom are well-known internationally.
Split into simpler sentences: Jonas Vaitkus has brought up a number of actors and directors. One of them is director Oskaras Koršunovas and actress Ingeborga Dapkūnaitė-who are well-known internationally.