Hello Goran,

When do we expect that it is included into Lucene=>Elasticsearch query conversion.

It already is included, and has been for 9 months, since version 5.10.2 was released: http://in.relation.to/2018/06/22/hibernate-search-5-10-2-Final/

If you use 5.9, then this feature is not included. Beside upgrading to 5.10 or 5.11, your only solution would be to rely on ElasticsearchQueries.fromJson, but that means writing the whole query directly as JSON.

And the second issue is why Lucene search in version <hibernate-search.version>5.5.4.Final</hibernate-search.version> for the given scenario above gave some result in the first place? it is not in compliance with https://www.elastic.co/guide/en/elasticsearch/reference/5.6/query-dsl-bool-query.html

If you I do not have enough information to answer that. My best guess is that your query is not what you think it is, or your should clause does match a document, or (unlikely) there is a bug in Lucene.

If you think there is a problem in Hibernate Search, you can try to create a reproducer based on our test case template.