select
EMP_CODE AS CODE,
EMP_LAST_NAME AS SURNAME,
EMP_FIRST_NAME as NAME
from 
EMP

where
REPLACE(EMP_LAST_NAME,' ','') || REPLACE(EMP_FIRST_NAME,' ','') 
in(
SELECT REPLACE(EMP_LAST_NAME,' ','') || REPLACE(EMP_FIRST_NAME,' ','')
FROM EMP
where
VALID_FLG = '1'
GROUP BY REPLACE(EMP_LAST_NAME,' ','') || REPLACE(EMP_FIRST_NAME,' ','')
having count(*) >= 2
)
AND
VALID_FLG = '1'
Order By 
REPLACE(EMP_LAST_NAME,' ','') || REPLACE(EMP_FIRST_NAME,' ',''),
EMP_CODE