Complex sentence: About ten hymns in the "Rigveda" are accredited to Maitreyi, and she discusses the Hindu concept of Atman (soul, self) in chapter 2.4 and repeated in 4.5 with some modifications of the "Brihadaranyaka Upanishad".
Split into simpler sentences: About ten hymns in the "Rigveda" are accredited to Maitreyi. She discusses the Hindu concept of Atman (soul, self) in the "Brihadaranyaka Upanishad".