Position hierarchy

SELECT
  LPAD (' ', 5 * LEVEL) || has.NAME hierarchy,
  LEVEL,
  hap.NAME parent_name,
  pse.parent_position_id,
  has.NAME child_name,
  pse.subordinate_position_id
FROM
  (SELECT NAME, position_id
  FROM hr_all_positions_f_tl
  WHERE LANGUAGE = USERENV ('LANG')) hap,
  (SELECT NAME, position_id
  FROM hr_all_positions_f_tl
  WHERE LANGUAGE = USERENV ('LANG')) has,
  per_pos_structure_elements pse
  WHERE pse.business_group_id = 81
  AND hap.position_id = pse.parent_position_id
  AND has.position_id = pse.subordinate_position_id
  start with pse.parent_position_id = 40979
CONNECT BY PRIOR pse.subordinate_position_id = pse.parent_position_id
AND PRIOR pse.pos_structure_version_id = pse.pos_structure_version_id
AND PRIOR pse.business_group_id = pse.business_group_id
ORDER BY 4