with tbl1 as (
select
    EMP_CODE
    , REPLACE(EMP_LAST_NAME, ' ', '') EMP_LAST_NAME 
    , REPLACE(EMP_FIRST_NAME, ' ', '') EMP_FIRST_NAME
    , REPLACE(EMP_LAST_NAME, ' ', '')||REPLACE(EMP_FIRST_NAME, ' ', '') name
from (select * from EMP where VALID_FLG='1') a
)
, tbl_count as (
select name, count(*) cnt
from tbl1
group by name
having cnt>1
)
select
    EMP_CODE CODE
    , EMP_LAST_NAME SURNAME
    , EMP_FIRST_NAME NAME
from tbl1 t
inner join tbl_count c on t.name=c.name
order by name, EMP_CODE