{
    "my_objects": [
    {
      "my_object_order": 1,
      "related_topics": [{"title": "my_title", "subtitle": "my_subtitle"}, {"title": "my_title2", "subtitle": "my_subtitle2"}],
      "collected_at": "2016-05-02T20:52:38.989Z",
    }
}

class TopicSerializer(serializers.ModelSerializer):
    class Meta:
        model = MyTopic
        fields = ["title", "subtitle"]

class MyObjectSerializer(serializers.ModelSerializer):

    related_topics = TopicSerializer(many=True)

    class Meta:
        model = MyObject
        fields = ("my_object_order",
                  "related_topics")

    def create(self, validated_data):
        """
        Saving serialized data
        """
        related_topics_list = validated_data.pop("related_topics", [])
        obj = MyObject.objects.create(**validated_data)
        for topics_data in related_topics_list:
            MyTopic.objects.create(trend=trend, **topics_data)
        return obj

def get(self, request):
    params = request.QUERY_PARAMS
    # Filtering data
    obj_list = my_fun(MyObject, params)
    response = {"my_objects": obj_list.values("my_object_order",
                                             "collected_at",
                                             "related_topics")}
    return Response(response)

{
    "my_objects": [
    {
      "my_object_order": 1,
      "related_topics": 5,
      "collected_at": "2016-05-02T20:52:38.989Z",
    }
}