WITH t AS
(
SELECT 'A' grp, 'S8755' id, 3 sub_id, 5220759 work_num FROM dual
UNION ALL SELECT 'B', 'S3712', 1, 5220768 FROM dual
UNION ALL SELECT 'B', 'S3712', 2, 5220768 FROM dual
UNION ALL SELECT 'B', 'S3712', 1, 5220769 FROM dual
UNION ALL SELECT 'B', 'S3712', 2, 5220769 FROM dual
)
SELECT grp
     , id
     , LISTAGG(sub_id) WITHIN GROUP(ORDER BY sub_id) sub_id
     , work_num
  FROM t
 GROUP BY grp, id, work_num
;