SELECT
      MEMBER
    , EMAIL
    , SUBSTR(DOMAIN_NAME, 1, INSTR(DOMAIN_NAME, '.') - 1) AS DOMAIN
FROM
    (
        SELECT
              MEMBER_CODE AS MEMBER
            , EMAIL
            , SUBSTR(EMAIL, INSTR(EMAIL, '@') + 1) AS DOMAIN_NAME
        FROM
            MEMBER_MST
    ) AS t
ORDER BY
      DOMAIN DESC
    , MEMBER DESC
;