1  with t as
  2  (     select 'A' name ,1 N from dual
  3  union select 'BB'     ,5   from dual
  4  union select 'C'      ,2   from dual
  5  )
  6* select * from t, xmltable('1 to xs:integer($n)' passing n as "n" columns rn  number path '.')
SQL> /

NA          N         RN
-- ---------- ----------
A           1          1
BB          5          1
BB          5          2
BB          5          3
BB          5          4
BB          5          5
C           2          1
C           2          2

8 rows selected.