SELECT 
    EMP_CODE AS CODE,
    EMP_LAST_NAME AS SURNAME,
    EMP_FIRST_NAME AS NAME
FROM
    (SELECT
        TRIM(EMP_LAST_NAME) AS A, 
        TRIM(EMP_FIRST_NAME) AS B,
        COUNT(EMP_LAST_NAME) AS CNT 
    FROM
        EMP
        GROUP BY A, B
        ) AS EMP_CNT
        
INNER JOIN 
    EMP
ON
    A = SURNAME 
AND
    B = NAME
AND 
    CNT > 1;