Você pode obter o que deseja usando isso:
select * from
(select name || ' ' || Surname Accounting from employees where depart_id = 1),
(select name || ' ' || Surname IT from employees where depart_id =2)
union
select * from
(select name || ' ' || Surname Accounting from managers where depart_id = 1),
(select name || ' ' || Surname IT from managers where depart_id =2)
