如何在角Kendo多选下拉列表的kendoMultiSelectHeaderTemplate中添加过滤器搜索选项？

Question

html

这是我使用的multiselect的html。我在kendoMultiSelectHeaderTemplate中放置了选择复选框。现在，我想在“选择”复选框下添加过滤器搜索选项。

                                <ng-template kendoMultiSelectItemTemplate let-dataItem>

                                    <input type="checkbox" class="k-checkbox" [checked]="isLangSelected(dataItem.text)">
                                    <label class="k-checkbox-label">{{ dataItem.text }}</label>

                                </ng-template>
                                <ng-template kendoMultiSelectGroupTagTemplate let-dataItems>
                                    <span>{{dataItems.length}} selected</span>
                                </ng-template>
                                <ng-template kendoMultiSelectHeaderTemplate>
                                    <span class="k-list">
                                        <span (click)="onClick()" class="k-item">
                                            <input type="checkbox" class="k-checkbox" [checked]="isChecked" />
                                            <label class="k-multiselect-checkbox k-checkbox-label">Show Selected Only</label>

                                        </span>
                                    </span>

                                </ng-template>
                                <ng-template kendoMultiSelectHeaderTemplate let-dataItem>
                                    <kendo-autocomplete [data]="data" [kendoDropDownFilter]="filterSettings" [placeholder]="'Search Language'">
                                    </kendo-autocomplete>
                                </ng-template>

                            </kendo-multiselect>