이거면 되는건가여 .

with v_data as (

select 'aaa-bbb+124' as kk from dual

union all select 'aaa-dfadf12bbb+124' as kk from dual

union all select 'aaa-dfaxx12bb+125' as kk from dual

)

select

substr(kk,1,instr(kk,'+') - 1)

from v_data

WITH t AS
(
SELECT 'aaaa-ccc+001' v FROM dual
UNION ALL SELECT 'bbbb-ddd+002' FROM dual
)
SELECT v
     , SUBSTR(v, 1, 8)               x1 -- 고정자리 자르기(고정자리 가정)
     , SUBSTR(v, 1, INSTR(v, '+')-1) x2 -- + 위치 이전까지 잘라내기
     , SUBSTR(v, 1, LENGTH(v)-4)     x3 -- 전체길이-4 만큼 잘라내기
     , REGEXP_REPLACE(v, '....$')    x4 -- 뒤에 4자리 없애기
     , RTRIM(v, '0123456789+')       x5 -- 오른쪽 숫자+ 제거(+앞 숫자 없다고 가정)
  FROM t
;