Describe the feature:
The basic idea is to be able to offer some kind of relations between documents, and then to create a filter that displays one attribute, and then filters by a different one.
A very basic example: imagine a list of sales, and you want to get the sales from people from a particular country. The current approach is to make sure that the 'sales' document has all the necessary fields, including the customer and the country of the customer.
The option that this plugin would offer is to have two sets of completely decoupled documents: sales, with the customer id, and a second one with the customer details, that contains, among other things, the customer id and the country. The plugin will be used to create a visualization that displays 'countries', and in fact filters by customer id.
Another minor improvement that this plugin offers is to have drop down and multiple select menus.
There is a prototype available at https://github.com/cernops/kibana-relational-filter
I wanted to know if this is something that might be interesting for other users, or if there is a better approach of doing this.