<TelerikPanelBar Data="@Items">
    <PanelBarBindings>
        <PanelBarBinding>
            <ContentTemplate>
                @{
                    var item = context as PanelBarItem;
                    <div onkeydown="stopPropagation(event)">
                        <TelerikTextArea @bind-Value="item.Text"></TelerikTextArea>
                    </div>
                }
            </ContentTemplate>
        </PanelBarBinding>
    </PanelBarBindings>
</TelerikPanelBar>

@* move this script to a separate file in production *@
<script suppress-error="BL9992">
function stopPropagation(e) {
    e.stopPropagation();
}
</script>

@code {
    public List<PanelBarItem> Items { get; set; }

    public class PanelBarItem
    {
        public string Text { get; set; }
        public List<PanelBarItem> Items { get; set; }
    }

    protected override void OnInitialized()
    {
        Items = new List<PanelBarItem>()
        {
            new PanelBarItem() { Text = "Item 1" },
            new PanelBarItem() { Text = "Item 2" }
        };
        base.OnInitialized();
    }
}