WITH dept AS
(
SELECT 10 dno, '영업본부' dnm, null p_dno FROM dual
UNION ALL SELECT 20, '영업1지점'          , 10 FROM dual
UNION ALL SELECT 40, '영업1팀'            , 20 FROM dual
UNION ALL SELECT 30, '영업2지점'          , 10 FROM dual
UNION ALL SELECT 50, '영업2지점 1조직'    , 30 FROM dual
UNION ALL SELECT 70, '영업2지점 1조직 1팀', 50 FROM dual
UNION ALL SELECT 80, '영업2지점 1조직 2팀', 50 FROM dual
UNION ALL SELECT 60, '영업2지점 2조직'    , 30 FROM dual
UNION ALL SELECT 90, '영업2지점 2조직 1팀', 60 FROM dual
)
, emp AS
(
SELECT 1 eno, 40 dno FROM dual
UNION ALL SELECT 2, 40 FROM dual
UNION ALL SELECT 3, 70 FROM dual
UNION ALL SELECT 4, 80 FROM dual
UNION ALL SELECT 5, 90 FROM dual
)
SELECT a.dnm
     , b.cnt
  FROM (SELECT ROWNUM rn
             , dno
             , LPAD(' ', (LEVEL-1)*4, ' ')||dnm dnm
          FROM dept
         START WITH p_dno IS NULL
         CONNECT BY PRIOR dno = p_dno
        ) a
     , (SELECT r_dno dno
             , COUNT(e.dno) cnt
          FROM (SELECT CONNECT_BY_ROOT dno r_dno
                     , dno
                  FROM dept
                 CONNECT BY PRIOR dno = p_dno
                ) d
             , emp e
         WHERE d.dno = e.dno(+)
         GROUP BY r_dno
        ) b
 WHERE a.dno = b.dno
 ORDER BY rn
;

마농님 감사합니다. 꾸벅