SELECT  piwosz
FROM    bywa b
WHERE   b.bar IN    (
            SELECT  p.bar
            FROM    podaja p
            WHERE   p.piwo IN   (
                        SELECT  l.piwo
                        FROM    lubi l
                        WHERE   l.piwosz = b.piwosz
                        )
            )

SELECT  piwosz
FROM    bywa b
    JOIN podaja p ON p.bar = b.bar
    JOIN lubi l ON l.piwo = p.piwo AND l.piwosz = b.piwosz