select 'AAAA' AA FROM DUAL
union
select 'bbbb' AA FROM DUAL
SELECT LEVEL as id,
REGEXP_SUBSTR(
'AAAA,BBBB,CCCC,DDDD,EEEE,FFFF'
, '[^,]+', 1, LEVEL, 'i') AS AA
FROM DUAL
CONNECT BY LEVEL <=5