I am planning to book a Club Europe return ticket for me in order to get to gold status. My 2 children (2 and 6) have to fly with me but I am not keen to pay business class for them. Can I buy 1 adult return business class ticket for earning tier points and get 2 children return business class with my avios for having my children with me?

Ba website does not seem to let me do this as my children would be considered as travelling unaccompanied. How can I book this?