The Brahma Sutra is attributed to Badarayana — which makes him the proponent of the crest-jewel school of Hindu philosophy, i.e., Vedanta.
Vyasa is conflated with Badarayana by Vaishnavas with the alleged reason that the island on which Vyasa was born is said to have been covered by Badara (Indian jujube/Ber/Ziziphus mauritiana) trees.
Apart from the early advaitin Adi Shankara (and his school) who refer to these two separately rather than as a single individual, many modern historians also think these were two different personalities.