WITH tb_master AS
(
SELECT 1 pk
     , TO_CLOB('I0000002619828A,I0000002619828A,I0000002619828A') v
  FROM dual
UNION ALL SELECT 2, TO_CLOB('a,b,c,d,e,f,g') FROM dual
)
SELECT pk
     , lv
     , CAST(REGEXP_SUBSTR(v, '[^,]+', 1, lv) AS VARCHAR2(50)) v
  FROM tb_master
     , (SELECT LEVEL lv FROM dual CONNECT BY LEVEL <= 99)
 WHERE lv <= LENGTH(v) - LENGTH(REPLACE(v, ',')) + 1
 ORDER BY pk, lv
;