导航栏 Bootstrap4 倍数行

Question

当组件过多时，如何配置 Bootstrap4 导航栏以将其调整为 2 行或更多行？

此导航栏是通过显示产品组的系统自动生成的。

        <nav class="navbar navbar-expand-md navbar-light bg-light" role="navigation">
    <div class="container">
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarCollapse">
            <span class="navbar-toggler-icon"></span>
        </button>
        <div id="navbarCollapse" class="collapse navbar-collapse">
            <ul class="navbar-nav" runat="server" id="navbar">
                <li class="nav nav-item dropdown"><a class="nav-link dropdown-toggle" runat="server" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false" href="#">INICIO</a>
                    <div class="dropdown-menu" aria-labelledby="navbarDropdown" runat="server" id="div_inicio_dropdown">
                        <a class="dropdown-item" href="Home.aspx">HOME</a>
                        <a class="dropdown-item" id="cmd_menu_mesas" runat="server" href="ComandaMesa.aspx">MESAS</a>
                        <a class="dropdown-item" href="ComandaMesaAberta.aspx?mes=0">COMANDAS ABERTA</a>
                    </div>
                </li>
            </ul>
        </div>
    </div>
</nav>