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