var PageSchema = new Schema({
  nr: { type: Number, required: true },
  content: { type: String }
});

var DocumentSchema = new Schema({
  created: { type: Date, default: Date.now },
  tags: [{ type: ObjectId, ref: "Tag" }],
  pages: { type: [PageSchema], es_indexed: true, es_type: "nested", es_include_in_parent: true }
});

DocumentSchema.plugin(mongoosastic);

var Document = mongoose.model('Document', DocumentSchema);

Document.search({
      multi_match: {
        fields: ["pages.content"],
        query: "oneone",
        fuzziness: "AUTO"
      }
    }, function(err, results) {
      if (err) return next(err);
      res.json(results);
    });

{
    "_shards": {
        "failed": 0,
        "successful": 5,
        "total": 5
    },
    "hits": {
        "hits": [
            {
                "_id": "5881d37a6e20aa66af14168c",
                "_index": "documents",
                "_score": 0.2876821,
                "_source": {
                    "pages": [
                        {
                            "content": "page oneone",
                            "nr": 1
                        },
                        {
                            "content": "page twotwo",
                            "nr": 2
                        }
                    ]
                },
                "_type": "document"
            }
        ],
        "max_score": 0.2876821,
        "total": 1
    },
    "timed_out": false,
    "took": 3
}

"pages": [
    {
        "content": "page oneone",
        "nr": 1
    }
]

"pages": [
    {
        "content": "page oneone",
        "nr": 1
    },
    {
        "content": "page twotwo",
        "nr": 2
    }
]