-- splitting as columns
select regexp_substr('a-b-c', '[^-]+', 1, 1) as grupo_1
      ,regexp_substr('a-b-c', '[^-]+', 1, 2) as grupo_2
      ,regexp_substr('a-b-c', '[^-]+', 1, 3) as grupo_3
  from dual;

-- result:
-- a b c

-- splitting as rows
 select regexp_substr('a-b-c', '[^-]+', 1, level) as one_element
   from dual
connect by regexp_substr('a-b-c', '[^-]+', 1, level) is not null;

-- result:
-- a
-- b
-- c