Can't really tell without knowing your mapping. But based on your answers I believe you did not define one.
Also I have no idea about what your framework is doing behind the scene. I don't understand how the nested thing is generated (and if you really need it).
And it's so easy to run some CRUD / search operations in Java that I always prefer doing that manually than delegating this to a framework.
( read http://david.pilato.fr/blog/2015/05/09/advanced-search-for-your-legacy-application/ )
I think you are using Hibernate. Have you tried the hibernate search integration with elasticsearch? I think it might be available (unsure though).