Question

The code behind file creates a list of employees and the asp.net page loops through list.
Now, How do I assign the employeedID to the commandArgument of an asp:button?

  <%foreach(var employee in employeesList){%>
    <tr>
     <td><%=employee.firstName%></td>
     <td><%=employee.lastName%></td>
    /*How to access employee.Id in the commandArgument? */
    <td><asp:Button ID="btnDeleteEmployee" runat="server" CommandArgument=''    Text="Delete" OnCommand="btnDeleteEmployee_Click" /></td>
    </tr>
<%}%>

Answer 1

Based on your comments, here is a nested example:

Markup:

<asp:Repeater runat="server" ID="rptOutter" 
    onitemdatabound="rptOutter_ItemDataBound" >
    <ItemTemplate>
        <tr>
            <td><%#Eval("firstName") %></td>
            <td><%#Eval("lastName") %></td>
            <td><asp:Button runat="server" ID="btnDeleteEmployee" CommandArgument='<%#Eval("Id") %>' Text="Delete" OnCommand="btnDeleteEmployee_Click"  /></td>
            <td>
                <asp:Repeater runat="server" ID="rptInner" >
                    <ItemTemplate>
                        <table>                                
                            <tr>
                                <td><%#Eval("firstNameInner") %></td>
                                <td><%#Eval("lastNameInner") %></td>
                            </tr>
                        </table>
                    </ItemTemplate>
                </asp:Repeater>

            </td>
        </tr>
    </ItemTemplate>
</asp:Repeater>

CodeBehind:

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        rptOutter.DataSource = outterDataSource;
        rptOutter.DataBind();
    }

}

protected void rptOutter_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    RepeaterItem item = e.Item;
    if ((item.ItemType == ListItemType.Item) ||
        (item.ItemType == ListItemType.AlternatingItem))
    {
        //get your datasource from parent repeater if needed
        //cast to your datasource type
        //DataSourceObject ds = (DataSourceObject)item.DataItem;
        Repeater r = e.Item.FindControl("rptInner") as Repeater;
        if (r != null)
        {
            r.DataSource = innerDataSource;
            r.DataBind();
        }
    }

}