with a as (
    select 
        EMP_CODE
        ,EMP_LAST_NAME
        ,EMP_FIRST_NAME
        ,replace(EMP_LAST_NAME,' ','') || replace(EMP_FIRST_NAME,' ','') as space_name
    from EMP 
    where VALID_FLG = '1'
)
select 
    t1.EMP_CODE as CODE
    ,t1.EMP_LAST_NAME as SURNAME
    ,t1.EMP_FIRST_NAME as NAME
from a t1
    inner join a t2
    on t1.space_name = t2.space_name
    and t1.EMP_CODE != t2.EMP_CODE
order by 
    t1.space_name
    ,t1.EMP_CODE