core: GraphQL: can't filter nested objects

Hello.

I try to filter nested entities. Example: I have the following schema: Entity 1<-* SubEntity 1<-* SubSubEntity. Each entity has string property Name.

When I add the following filter to Entity:

/**
 * @ApiResource()
 ...
 */
class Entity
{
    /**
     * @ApiFilter(SearchFilter::class, properties={"name": "ipartial"})
     */
    private $subEntities;
}

this query works fine:

{
  entities {
    subEntities (name: "Name") {
    ...
    }
  }
}

I get all the entities with filtered subEntities.

But when I add new filter:

...
    /**
     * @ApiFilter(SearchFilter::class, properties={"name": "ipartial"})
     * @ApiFilter(SearchFilter::class, properties={"subSubEntities": "exact"})
     */
    private $subEntities;

or

...
    /**
     * @ApiFilter(SearchFilter::class, properties={"name": "ipartial"})
     * @ApiFilter(SearchFilter::class, properties={"subSubEntities.name": "ipartial"})
     */
    private $subEntities;

The Schema builder even doesn’t see this second filter. I suspect that the reason is that the new filter is not of scalar type, but an object.

Am I doing something wrong or it’s a bug?