Support for Nested Text Fields

[karansampath]

Currently, the query_field parameter used for the ElasticSearchstore class does not support a nested field since it directly queries the name from the dictionary. This impedes using existing indexes with nested text fields, and would be a simple and useful change.

[miguelgrinberg]

We'll have to think about this one. My assumption was that langchain wants a text field, so I'm not sure if fitting a nested field there is possible. But in any case, you can create a custom strategy class that issues the query that you want. Have you considered doing that?