Image courtesy: Brig A.P. Singh - www.collectingmoment.in
Hoysaleshwara temple is dedicated to Lord Shiva hence the easy conclusion would be that this sculpture is of Shiva and Parvathi. However, looking at the statue, the male deity here is holding the Conch shell (Shankha) and Chakra (discuss) which means it is Lord Vishnu. Hoysala royals were known patrons of Lord Vishnu but both Shaivism and Jainism thrived under their support.