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