Com cte recursivo indo de cima para filho:
with cte as(
select *, code as ultimate from t where code = under
union all
select t.*, c.ultimate from t
join cte c on c.code = t.under
where t.code <> t.under
)
select * from cte
Para dados:
create table t (code int, name varchar(100), under int)
insert into t values
(1, 'National Sales Manager', 1),
(2, 'regional sales manager', 1),
(3, 'area sales manager', 2),
(4, 'sales manager', 3),
(5, 'a', 5),
(6, 'b', 5),
(7, 'c', 5),
(8, 'd', 7),
(9, 'e', 7),
(10, 'f', 9),
(11, 'g', 9)
ele gera a saída:
code name under ultimate
1 National Sales Manager 1 1
5 a 5 5
6 b 5 5
7 c 5 5
8 d 7 5
9 e 7 5
10 f 9 5
11 g 9 5
2 regional sales manager 1 1
3 area sales manager 2 1
4 sales manager 3 1
Fiddle http://sqlfiddle.com/#!6/17c12e/1
