Get ID of Panel when Button inside Panel is clicked in ASP.Net

Make single click event for three Buttons In which you can find button who raise the event also find the parent control (Div tag) of button control .

Refer below sample for your refrence.

 Page.aspx 

    <form id="form1" runat="server">
    <div id="dvFirst" runat="server">
        <asp:Button ID="btnFirst" runat="server" Text="First" OnClick="ButtonClick" />
    </div>
    <br />
    <div id="divSecond" runat="server">
        <asp:Button ID="btnSecond" runat="server" Text="Second" OnClick="ButtonClick" />
    </div>
    <br />
    <div id="divThired" runat="server">
        <asp:Button ID="btnThired" runat="server" Text="Thired" OnClick="ButtonClick" />
    </div>
    <br />
    <asp:Label ID="lblDisplay" runat="server"></asp:Label>
    </form> 

Page.aspx.cs 

   protected void ButtonClick(object sender, EventArgs e)
    {
        lblDisplay.Text = "";
        string btn, div;
        Button button = (sender as Button);
        btn = button.Text;
        div = button.Parent.ClientID.ToString();
        this.lblDisplay.Text = "You have Clicked " + btn + " Button " + " From " + div + " Tag.";
    }