Context and motivation

The recently created for intersection filter could accept a range of value as long as we are able to build something like this in the filters:

value_start BETWEEN date_start AND date_end OR
value_end BETWEEN date_start AND date_end OR
(value_start <= date_start AND value_end >= date_start)

However, to do so our WP_Query would need nested metaqueries with different relation and that is something our filter components are not ready to.

Ideal solution

Work on accepting different relation arrays. The challenge is to map a query to its original metadata and filter, generating proper tags, etc... This is also needed for #841