select regexp_replace(텍스트, '[^0-9]') from 테이블;

select substr(txt,instr(txt,'-') + 1, (instr(txt,',') - instr(txt,'-')) -1) from 테이블;

--이렇게 하시면 되지 않을까요?

WITH t AS
(
SELECT '제품-11231G, 사과1K' v FROM dual
UNION ALL SELECT '제품-2120S, 감5C' FROM dual
UNION ALL SELECT '제품-555A, 배3A'  FROM dual
)
SELECT v
     , REGEXP_REPLACE(v, '.+-|,.+') x
     , SUBSTR(v, INSTR(v, '-') + 1, INSTR(v, ',') - INSTR(v, '-') - 1) y
     , SUBSTR(v, 4, INSTR(v, ',') - 4) z  -- 항상 "제품-"로 시작한다면?
  FROM t
;