Im co-author of Searchkit (www.searchkit.co). This Hierarchical filtering demo uses Elasticsearch aggregations on nested documents with our Hierarchical filter component.<p>For more info see
<a href="http://docs.searchkit.co/stable/docs/components/navigation/hierarchical-refinement-filter.html" rel="nofollow">http://docs.searchkit.co/stable/docs/components/navigation/h...</a><p>and<p><a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-nested-aggregation.html" rel="nofollow">https://www.elastic.co/guide/en/elasticsearch/reference/curr...</a>