Set selected option in Bootstrap DropDown Menu list selection using jQuery in ASP.Net

Hi nedash,

Refer below code.

HTML

<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
<script type="text/javascript">
    $(function () {
        $(".dropdown-menu li a").click(function () {
            $(this).closest('.dropdown').find(".btn:first-child").text($(this).text());
            $(this).closest('.dropdown').find(".btn:first-child").val($(this).text());
        });
    });
</script>
<div class="dropdown">
    <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton"
        data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        واگذاری را انتخاب نمایید
    </button>
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
        <asp:Repeater ID="rptTran" runat="server">
            <ItemTemplate>
                <li><a target="_blank" class="dropdown-item" id="btnsystem" runat="server" commandargument='<%# Eval("Transfer") %>'>
                    <%# Eval("Transfer") %></a></li>
            </ItemTemplate>
        </asp:Repeater>
    </div>
</div>
<br />
<div class="dropdown">
    <button class="btn btn-secondary dropdown-toggle" type="button" id="Button1" data-toggle="dropdown"
        aria-haspopup="true" aria-expanded="false">
        Menu 2
    </button>
    <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
        <asp:Repeater ID="Repeater1" runat="server">
            <ItemTemplate>
                <li><a target="_blank" class="dropdown-item" id="btnsystem" runat="server" commandargument='<%# Eval("Transfer") %>'>
                    <%# Eval("Transfer") %></a></li>
            </ItemTemplate>
        </asp:Repeater>
    </div>
</div>

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.Add("Transfer");
        dt.Rows.Add("Transfer 1");
        dt.Rows.Add("Transfer 2");
        dt.Rows.Add("Transfer 3");
        dt.Rows.Add("Transfer 4");
        rptTran.DataSource = dt;
        rptTran.DataBind();
        Repeater1.DataSource = dt;
        Repeater1.DataBind();
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As System.Data.DataTable = New System.Data.DataTable()
        dt.Columns.Add("Transfer")
        dt.Rows.Add("Transfer 1")
        dt.Rows.Add("Transfer 2")
        dt.Rows.Add("Transfer 3")
        dt.Rows.Add("Transfer 4")
        rptTran.DataSource = dt
        rptTran.DataBind()
        Repeater1.DataSource = dt
        Repeater1.DataBind()
    End If
End Sub

Screenshot