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||EMP_FIRST_NAME,' ','') IN(
  SELECT
    REPLACE(EMP_LAST_NAME||EMP_FIRST_NAME,' ','') as EMP_NAME
  FROM EMP
  WHERE VALID_FLG = '1'
  GROUP BY EMP_NAME
  HAVING COUNT(*) > 1)
ORDER BY REPLACE(EMP_LAST_NAME||EMP_FIRST_NAME,' ','') asc,CODE asc