.Net RunTimeBinderException

I have a data content witch contains complex data I just need index names which seem in Dynamic View in data. In debug mode I can see the datas but cant get them..

You can see the contents of data in image below):

 if(hits.Count() > 0)
            {
                var data = hits.FirstOrDefault().Source;
                var dataaa = JsonConvert.DeserializeObject(hits.FirstOrDefault().Source);
            }

I found a solution with checking if selected index has documents; if yes, I take the first document in index, and parse it to keys(field names) in client. here is my func:

[HttpPost]
        public ActionResult getIndexFields(string index_name)
        {
            var node = new Uri("http://localhost:9200");
            var settings = new ConnectionSettings(
                node,
                defaultIndex: index_name
            );
            var esclient = new ElasticClient(settings);
            var Documents = esclient.Search<dynamic>(s => s.Index(index_name).AllTypes().Source());
            string fields = "";
            if (Documents.Documents.Count() > 0)
            {
                fields = JsonConvert.SerializeObject(Documents.Documents.FirstOrDefault());
                var data = Documents.Documents.FirstOrDefault().Source;
                return Json(new
                {
                    result = fields,
                    Success = true
                });
            }

            return Json(new
            {
                result = "",
                Success = false
            });

        }

and my js:

$.ajax({
            url: "getIndexFields?index_name=" + $(this).val(),
            type: "POST",
            success: function (data) {
                if (data.Success) {
                    var fields = JSON.parse(data.result);
                    var fields_arr = [];
                    $.each(fields, function (value, index) {
                        fields_arr.push(
                            {
                                id: value,
                                label: value
                            })
                    });
                    options.filters = fields_arr;
                    var lang = "en";//$(this).val();

                    var done = function () {
                        var rules = $b.queryBuilder('getRules');
                        if (!$.isEmptyObject(rules)) {
                            options.rules = rules;
                        }
                        options.lang_code = lang;
                        $b.queryBuilder('destroy');
                        $('#builder').queryBuilder(options);
                    };
                    debugger
                    if ($.fn.queryBuilder.regional[lang] === undefined) {
                        $.getScript('../dist/i18n/query-builder.' + lang + '.js', done);
                    }
                    else {
                        done();
                    }
                }
                else {
                    event.theme = 'ruby';
                    event.heading = '<i class=\'fa fa-warning\'></i> Process Failure';
                    event.message = 'User could not create.';
                    event.sticky = true;
                    $("#divfailed").empty();
                    $("#divfailed").hide();
                    $("#divfailed").append("<i class='fa fa-warning'></i> " + data.ErrorMessage);
                    $("#divfailed").show(500);
                    setTimeout(function () {
                        $("#divfailed").hide(500);
                    }, 3000);
                }
            },
            error: function (a, b, c) {
                debugger
                event.theme = 'ruby';
                event.heading = '<i class=\'fa fa-warning\'></i> Process Failure';
                event.message = 'Object could not create.';
                $("#divfailed").empty();
                $("#divfailed").hide();
                msg = c !== "" ? c : a.responseText;
                $("#divfailed").append("<i class='fa fa-warning'></i> " + msg);
                $("#divfailed").show(500);
                setTimeout(function () {
                    $("#divfailed").hide(500);
                }, 3000);
            }
        });