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