select regexp_substr('bbb,aaa,ccc', '[^,]+', 1, level) as split_result
  from dual
connect by level <=
           length('bbb,aaa,ccc') - length(replace('bbb,aaa,ccc', ',')) + 1;

select regexp_substr(replace('aaa;bbb;ccb', '', ';'), '[^;]+', 1, level) as split_result
   from dual
 connect by level <= regexp_count('aaa;bb;', ';') + 1;

with temp as
 (select 'bbb,aaa,ccc' as str from dual)
select regexp_substr(replace(str, ',', ' ,'), '[^,]+', 1, level)
  from temp
connect by level <= regexp_count(str, ',') + 1

select split_result,length(split_result) from (
 select regexp_substr(replace('aaa;bb;', '', ';'), '[^;]+', 1, level) as split_result
   from dual
 connect by level <= regexp_count('aaa;bb;', ';') + 1)
 where split_result is not null;

create or replace type result_split_list as table of varchar2(100);

create or replace function split_strs(strs varchar2, type_split varchar2)
  return result_split_list
  pipelined is
  index_num  pls_integer;
  str_list varchar2(100) := strs;
begin
  loop
    index_num := instr(str_list, type_split);
    if index_num > 0 then
      pipe row(substr(str_list, 1, index_num - 1));
      str_list := substr(str_list, index_num + length(type_split));
    else
      pipe row(str_list);
      exit;
    end if;
  end loop;
  return;
end split_strs;

select * from table (select split_strs('aaa,bbb,ccc',',') from dual);