In the initial Highlit API implementation we’ve blocked the highlights in the nested context (using highlight() inside object() projections), as well as highlights on the fields of nested objects that are of ObjectStructure.NESTED structure.

To add this back, we’d need to work with Elasticsearch’s inner hits

As for the Lucene case – we’d at least need to modify the queries used in highlighting to get rid of ToParentBlockJoinQuery or to extract its inner queries correctly…