SELECT *
FROM (
    SELECT
        posts.col1 AS emp_id,
        posts.col2 AS dept_id,
        posts.col3 AS posts,
        DENSE_RANK() OVER post_ranking AS rank
    FROM VALUES
        (1, 1 ,100),
        (2, 1 ,50),
        (8, 1 ,250),
        (3, 2 ,200),
        (4, 2 ,300),
        (9, 2 ,1000),
        (5, 3 ,300),
        (6, 3 ,100),
        (7, 3 ,400) AS posts
    WINDOW post_ranking AS (
        PARTITION BY posts.col2
        ORDER BY posts.col3 DESC
    ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
)
WHERE rank <= 2;
