Нечто подобное должно сблизить вас.
select
e.first_name
, e.last_name
, m.first_name as 'manager first name'
, m.last_name as 'manager last name'
, d.name
from employee e
inner join dept d
left outer join employee m on d.manager_id = m.id
on e.dept_id = d.dept_id