Navbar

Create a navigation bar with a dropdown menu.

        
            <nav class="navbar navbar-expand-lg navbar-light bg-light p-3">
                <a href="#" class="navbar-brand text-uppercase text-dark">Logo</a>
                <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarToggle" aria-controls="navbarToggle" aria-expanded="false" aria-label="Toggle main navigation">
                    <i class="fas fa-bars fa-lg"></i>
                </button>
                <div class="collapse navbar-collapse" id="navbarToggle">
                    <ul class="navbar-nav ml-auto">
                        <li class="nav-item dropdown">
                            <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                                Multicolumn<i class="fas fa-angle-down ml-2"></i>
                            </a>
                            <div class="dropdown-menu dropdown-menu-lg dropdown-menu-center" aria-labelledby="dropdownMenuButton">
                                <div class="row no-gutters">
                                    <div class="col">
                                        <div class="dropdown-header">Title</div>
                                        <a class="dropdown-item" href="#">Item 1</a>
                                        <a class="dropdown-item" href="#">Item 2</a>
                                        <a class="dropdown-item" href="#">Item 3</a>
                                        <a class="dropdown-item" href="#">Item 4</a>
                                    </div>
                                    <div class="col">
                                        <div class="dropdown-header">Title</div>
                                        <a class="dropdown-item" href="#">Item 1</a>
                                        <a class="dropdown-item" href="#">Item 2</a>
                                        <a class="dropdown-item" href="#">Item 3</a>
                                        <a class="dropdown-item" href="#">Item 4</a>
                                    </div>
                                </div>
                            </div>
                        </li>
                        <li class="nav-item">
                            <a class="nav-link" href="#">Item</a>
                        </li>
                        <li class="nav-item">
                            <a class="nav-link" href="#">Item</a>
                        </li>
                        <li class="nav-item dropdown">
                       <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                           Dropdown<i class="fas fa-angle-down ml-2"></i>
                       </a>
                       <div class="dropdown-menu" aria-labelledby="navbarDropdown">
                           <a class="dropdown-item" href="#">Item 1</a>
                           <a class="dropdown-item" href="#">Item 2</a>
                           <a class="dropdown-item" href="#">Item 3</a>
                       </div>
                   </li>
                    </ul>
                </div>
            </nav>
        
    

Boost theme includes two new classes: .dropdown-menu-lg for wider dropdowns (e.g: a 2 column menu) and .dropdown-menu-center to center align it.

Bootstrap Documentation