After a prātipadika (Nominal Stem) ending in the Genitive 6th-Case comes the affix rūpya and also caraṭ in the sense of 'having belonged formerly to somebody'.,
The word भूतपूर्व here qualifies the sense of the affix, and not the sense of the base, as it in the last sutra. Thus देवदत्तस्य भूतपूर्वो गौः = देवदत्तरूप्यः 'the cow that formerly belonged to Devadatta'. Similarly देवदत्तचरः ॥,