SELECT 
  E.EMP_CODE AS CODE
  , E.EMP_LAST_NAME AS SURNAME
  , E.EMP_FIRST_NAME AS NAME
FROM
  EMP E
  INNER JOIN (
      SELECT 
        REPLACE(EMP_LAST_NAME, ' ', '') AS TEMP_SURNAME
        , REPLACE(EMP_FIRST_NAME, ' ', '') AS TEMP_NAME
      FROM
        EMP
      WHERE
        VALID_FLG = '1'
      GROUP BY
        REPLACE(EMP_LAST_NAME, ' ', '')
        , REPLACE(EMP_FIRST_NAME, ' ', '')
      HAVING
        COUNT(*) > 1
    ) T
  ON
    REPLACE(E.EMP_LAST_NAME, ' ', '') = T.TEMP_SURNAME
    AND REPLACE(E.EMP_FIRST_NAME, ' ', '') = T.TEMP_NAME
WHERE
  VALID_FLG = '1'
ORDER BY
  replace(E.EMP_FIRST_NAME, ' ', '') ASC
  , E.EMP_CODE ASC
;