Complex sentence: Her play "Její pastorkyňa" was the basis for the opera "Jenůfa" by Leoš Janáček, whose earlier opera "The Beginning of a Romance" was also based on one of her stories.
Split into simpler sentences: Her play "Její pastorkyňa" was the basis for the opera "Jenůfa" by Leoš Janáček. His earlier opera "The Beginning of a Romance" was also based on one of her stories.