SELECT
EMP_CODE AS CODE,
EMP_LAST_NAME AS SURNAME,
EMP_FIRST_NAME AS NAME
FROM EMP
 
WHERE 
VALID_FLG = '1'
AND REPLACE (EMP_LAST_NAME || EMP_FIRST_NAME, ' ', '') IN (
 SELECT
  REPLACE (EMP_LAST_NAME || EMP_FIRST_NAME, ' ', '') AS EMP_NAME
 FROM
  EMP
 WHERE
  VALID_FLG = '1'
 GROUP BY
  EMP_NAME
 HAVING
  COUNT(*) >= 2
)
ORDER BY
REPLACE (EMP_LAST_NAME || EMP_FIRST_NAME, ' ', '') ASC,
EMP_CODE ASC;