-- WITH fails: Column alias is not specified for expression "(COUNT(CUSTOMER_ID) > 1)";
WITH d AS (
        SELECT customer_id
        FROM (  SELECT DISTINCT
                    customer_id
                    , id_customer_type
                FROM risk.ext_counterparty_classification )
        GROUP BY customer_id
        HAVING Count( customer_id ) > 1 )
SELECT *
FROM risk.ext_counterparty_classification a
    INNER JOIN d
            on a.customer_id = d.customer_id
WHERE id_customer_type = 'Multi Financial Institution'
;


-- although SUB Select works
SELECT *
FROM risk.ext_counterparty_classification a
    INNER JOIN (    SELECT customer_id
                    FROM (  SELECT DISTINCT
                                customer_id
                                , id_customer_type
                            FROM risk.ext_counterparty_classification )
                    GROUP BY customer_id
                    HAVING Count( customer_id ) > 1 ) d
        ON a.customer_id = d.customer_id
WHERE id_customer_type = 'Multi Financial Institution'
;