Complex sentence: Apart from the two sisters, keyboardist Matmat Lumagsao is also the sister of the band's manager Lito, while his (Lito's) wife, Josie, is Rey's sister.
Split into simpler sentences: Apart from the two sisters, keyboardist MAtMAt LUmAgsaO is also the sister of the band's manager Lito. While his (Lito's) wife, Josie, is Rey's sister.