Is it possible to compute the bitmapAndCardinality, which params come from different tables in a parallel way?

[mo-avatar]

SELECT bitmapAndCardinality(user1,user2)
FROM (
SELECT 1 AS join_id,groupBitmap(toUInt32(did)]) AS user1
FROM t_r_1_local where region='Moscow') as a
INNER JOIN(
SELECT 1 AS join_id,groupBitmap(toUInt32(did)]) AS user2
FROM t_r_2_local where age=20) as b on a.join_id=b.join_id

In order to calculate the number of de-duplicated result of users in different user groups, we use the sql above。
but more user groups slows down the sql performance.
cause the computation process of groupBitmap with join are processed one by one.

Except for wide table, is there any moves which we can take to improve the performance?
Any suggestion will be welcomed (Including do some kernel modification)