Два выпадающих списка Episerver подключены

Существует решение на EPiServer World для аналогичной проблемы. Он активно использует додзё. Если вам действительно нужны 2 отдельных раскрывающихся списка, вы можете попробовать их.

Добавление кода Андерсом Хаттестадом на случай, если статья будет недоступна здесь:

    class DependedItem : ISelectItem
    {
        public string Parent { get; set; }
        public object Value { get; set; }
        public int Level { get; set; }
        public string Text { get; set; }
        public string Name { get { return Text; } }
    }

    public class ContinentCountryRegionSelectionFactory : ISelectionFactory
    {
        public IEnumerable<ISelectItem> GetSelections(ExtendedMetadata metadata)
        {
            var _geolocationProviderBase = ServiceLocator.Current.GetInstance<GeolocationProviderBase>();
            var _localizationService = ServiceLocator.Current.GetInstance<LocalizationService>();
            var list = new List<ISelectItem>();
            foreach (var continentKey in _geolocationProviderBase.GetContinentCodes())
            {
                var continent = new DependedItem()
                {
                    Value = continentKey,
                    Parent = "",
                    Level=0,
                    Text = _localizationService.GetString("/shell/cms/visitorgroups/criteria/geographiclocation/continents/" + continentKey)
                };
                list.Add(continent);
                foreach (var countryKey in _geolocationProviderBase.GetCountryCodes(continentKey))
                {
                    var country = new DependedItem()
                    {
                        Value = continentKey+"-"+ countryKey,
                        Parent= continentKey,
                        Level=1,
                        Text = _localizationService.GetString("/shell/cms/visitorgroups/criteria/geographiclocation/countries/" + countryKey)
                    };

                    list.Add(country);

                    foreach (var regionKey in _geolocationProviderBase.GetRegions(countryKey))
                    {
                        var region = new DependedItem()
                        {
                            Value = continentKey + "-" + countryKey+"-"+ regionKey,
                            Parent= continentKey + "-" + countryKey,
                            Level=2,
                            Text = regionKey
                        };
                        list.Add(region);
                    }
                }
            }

            return list;
        }
    }

/*
Dojo widget for editing a list of strings. Also see property type PropertyStringList in /Models/Properties.
*/

define([
    "dojo/_base/array",
    "dojo/_base/connect",
    "dojo/_base/declare",
    "dojo/_base/lang",

    "dijit/_CssStateMixin",
    "dijit/_Widget",
    "dijit/_TemplatedMixin",
    "dijit/_WidgetsInTemplateMixin",

    "dijit/form/TextBox",

    "epi/epi",
    "epi/shell/widget/_ValueRequiredMixin",
    "dojo/store/Memory",
    "dijit/form/FilteringSelect"
],
function (
    array,
    connect,
    declare,
    lang,

    _CssStateMixin,
    _Widget,
    _TemplatedMixin,
    _WidgetsInTemplateMixin,

    Textarea,
    epi,
    _ValueRequiredMixin,

    Memory,
    FilteringSelect
) {

    return declare([_Widget, _TemplatedMixin, _WidgetsInTemplateMixin, _CssStateMixin, _ValueRequiredMixin], {

        templateString: "<div class=\"dijitInline\">\
                            <div data-dojo-attach-point=\"stateNode, tooltipNode\"  >\
                                <div data-dojo-attach-point=\"textBox\" type=\"hidden\" data-dojo-type=\"dijit.form.TextBox\"></div>\
                            </div>\
                            <div data-dojo-attach-point=\"inputLevel1\" data-dojo-type=\"dijit.form.FilteringSelect\" style=\"min-width: 300px;\">\
                            </div>\
                            <div data-dojo-attach-point=\"area2\" style=\"display:block;padding-left:30px;display:none;\">\
                                <div data-dojo-attach-point=\"inputLevel2\" data-dojo-type=\"dijit.form.FilteringSelect\" style=\"min-width: 300px;\">\
                                </div>\
                                <div data-dojo-attach-point=\"area3\" style=\"display:block;padding-left:30px;display:none;\">\
                                    <div data-dojo-attach-point=\"inputLevel3\" data-dojo-type=\"dijit.form.FilteringSelect\" style=\"min-width: 300px\">\
                                    </div>\
                                </div>\
                            </div>\
                        </div>",
        intermediateChanges: false,
        value: null,
        allItemsStore: null,
        selected: null,
        onChange: function (value) {
            // Event
        },

        postCreate: function () {
            // call base implementation
            this.inherited(arguments);

            // Init textarea and bind event
            this.textBox.set("intermediateChanges", this.intermediateChanges);
            this.connect(this.textBox, "onChange", this._onTextBoxChanged);
            this._setUpStores(1);
            this.selected = this._findSelected("");
            this.connect(this.inputLevel1, "onChange", this._onLevelBoxChanged1);
            this.connect(this.inputLevel2, "onChange", this._onLevelBoxChanged2);
            this.connect(this.inputLevel3, "onChange", this._onLevelBoxChanged3);
        },
        postMixInProperties: function () {
            this.inherited(arguments);
            var test = this.selections;

            this.allItemsStore = new Memory({ idProperty: "value", IsType: "Continent", data: this.selections });
        },
        isValid: function () {
            return !this.required || (this.value.length > 0 && this.value!= "");
        },

        // Setter for value property
        _setValueAttr: function (value) {
            this._setValue(value, true,true);
        },

        _setReadOnlyAttr: function (value) {
            this._set("readOnly", value);
            this.textBox.set("readOnly", value);
        },

        _setIntermediateChangesAttr: function (value) {
            this.textBox.set("intermediateChanges", value);
            this._set("intermediateChanges", value);
        },

        _onTextBoxChanged: function (value) {
            this._setValue(value, false,false);
        },
        _onLevelBoxChanged1: function (value) {
            var me = this._findSelected(value);
            //this.selected = this._findSelected(value);
            if (this.selected.level1 != me.level1) {
                this.selected = me;
                this._setUpStores(2);
                this._setValuesInDropDowns();
                this._setValue(value, true, false);
            } else {
                //this._setValue(value, true, false);
            }
        },
        _onLevelBoxChanged2: function (value) {
            var me = this._findSelected(value);
            if (this.selected.level2!=me.level2)
            {
                this.selected = me;
                this._setUpStores(3);
                this._setValuesInDropDowns();
                this._setValue(value, true, false);
            }
            //this._setUpStores();
            //this._setValue(value, true,false);
        },
        _onLevelBoxChanged3: function (value) {
            var me = this._findSelected(value);
            if (this.selected.level3 != me.level3) {
                this.selected = me;
                //this._setUpStores(3);
                this._setValuesInDropDowns();
                this._setValue(value, true, false);
            }
        },
        _findSelected: function (value) {
            var result = { level1: "", level2: "", level3: "" };
            var item = this.allItemsStore.query({ value: value });

            if (item.length != 0) {
                 if (item[0].level == 2) {
                     result.level3 = item[0].value;
                     item = this.allItemsStore.query({ value: item[0].parent });
                 }
                 if (item[0].level == 1) {
                     result.level2 = item[0].value;
                     item = this.allItemsStore.query({ value: item[0].parent });
                 }
                if (item[0].level == 0) {
                    result.level1 = item[0].value;
                }
            }
            return result;
        },
        _setValuesInDropDowns: function () {
            this.inputLevel1.set("value", this.selected.level1);
            this.inputLevel2.set("value", this.selected.level2);
            this.inputLevel3.set("value", this.selected.level3);
            this.area2.style.display=(this.selected.level1!="")?"block":"none";
            this.area3.style.display=(this.selected.level2!="")?"block":"none";
        },
        _setUpStores: function (level) {
            if (level == 1 || level == 0) {
                var level1 = this.allItemsStore.query({ level: 0 });
                var level1Store = new Memory({ idProperty: "value", data: level1 });
                this.inputLevel1.set("store", level1Store);
            }

            if ((level == 2 || level == 0) && this.selected.level1 != "") {
                var level2 = this.allItemsStore.query({ level: 1, parent: this.selected.level1});
                var level2Store = new Memory({ idProperty: "value", data: level2 });
                this.inputLevel2.set("store", level2Store);
            }
            if ((level == 3 || level == 0) && this.selected.level2 != "") {
                var level3 = this.allItemsStore.query({ level: 2, parent: this.selected.level2 });
                var level3Store = new Memory({ idProperty: "value", data: level3 });
                this.inputLevel3.set("store", level3Store);
            }



        },
        _setValue: function (value, updateTextbox,updateDropDown) {
            if (updateDropDown) {
                this.selected = this._findSelected(value);
                this._setUpStores(0);
                this._setValuesInDropDowns();
            }
            if (this._started && epi.areEqual(this.value, value)) {
                return;
            }

            // set value to this widget (and notify observers)
            this._set("value", value);

            // set value to textarea
            if (updateTextbox) {
                this.textBox.set("value", value);

            }


            if (this._started && this.validate()) {
                // Trigger change event
                this.onChange(value);
            }
        }
    });
});

[ClientEditor(ClientEditingClass = "iterasite/editors/SelectAreaEditor", SelectionFactoryType = typeof(ContinentCountryRegionSelectionFactory))]
public virtual string SelectArea { get; set; }