WITH SAME AS
(SELECT
REPLACE(EMP_LAST_NAME,' ','') || REPLACE(EMP_FIRST_NAME,' ','') AS FNAME
FROM EMP
WHERE VALID_FLG = 1
GROUP BY FNAME
HAVING COUNT(*) >=2)

SELECT
EMP_CODE AS CODE,
EMP_LAST_NAME AS SURNAME,
EMP_FIRST_NAME AS NAME
FROM EMP
JOIN SAME AS S
ON REPLACE(EMP.EMP_LAST_NAME,' ','') || REPLACE(EMP.EMP_FIRST_NAME,' ','') = S.FNAME
ORDER BY S.FNAME,EMP_CODE
;