<div class="container">
  <nav class="navbar navbar-default">
    <div class="navbar-header">
    </div>

    <div class="collapse navbar-collapse js-navbar-collapse text-center collapse in" style="padding:0;">
      <ul class="nav navbar-nav" style="float:none;">
        <li class="dropdown mega-dropdown">
            <a href="" class="dropdown-toggle" data-toggle="dropdown" style="color:#fff;">Menu 1 </a>  
        </li>
        <li class="dropdown mega-dropdown-one">
            <a href="" class="dropdown-toggle" data-toggle="dropdown" style="color:#fff;">Menu 2 <i class="fa fa-chevron-down" aria-hidden="true"></i></a>  
            <ul class="dropdown-menu mega-dropdown-menu row">
                <li class="col-sm-3">
                    <a href="#">Submenu 1</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 2</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 3</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 4</a>
                </li>
            </ul>
        </li>
        <li class="dropdown mega-dropdown-two">
            <a href="" class="dropdown-toggle" data-toggle="dropdown" style="color:#fff;">Menu 3 <i class="fa fa-chevron-down" aria-hidden="true"></i></a>  
            <ul class="dropdown-menu mega-dropdown-menu row">
                <li class="col-sm-3">
                    <a href="#">Submenu 1</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 2</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 3</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 4</a>
                </li>
                <li class="col-sm-3">
                    <a href="#">Submenu 5</a>
                </li>
            </ul>
        </li>
      </ul>
    </div>
    <!-- /.nav-collapse -->
  </nav>
</div>

.mega-dropdown,
.mega-dropdown-one {
    width: 33.3%;
    display: inline-block
}

.mega-dropdown-one,
.mega-dropdown-two {
    position: static!important;
    display: inline-block
}

.mega-dropdown {
    background:linear-gradient(to right,#294594,#528ce4);
}

.mega-dropdown-one {
    background: linear-gradient(to right,#07ddff,#16a28f);
}

.mega-dropdown-two {
    background:linear-gradient(to right,#386ee8,#7da0de);
    color: #fff;
    width: 33.4%
}

.navbar-default .navbar-nav>.open>a,
.navbar-default .navbar-nav>.open>a:focus,
.navbar-default .navbar-nav>.open>a:hover {
    background-color: #b3b2b2;
    color: #fff
}

@media (max-width:769px) {
    .mega-dropdown,
    .mega-dropdown-one,
    .mega-dropdown-two {
        width: 100%;
        display: inline-block
    }
    .mega-dropdown {
        background-color: #2aaab6
    }
    .mega-dropdown-one {
        position: static!important;
        background-color: #f4af00
    }
    .mega-dropdown-two {
        position: static!important;
        background-color: #fb6e69;
        color: #fff
    }
    .navbar-nav {
        margin: 0;
        text-align: center
    }
    .mega-dropdown-one .mega-dropdown-menu:after,
    .mega-dropdown-one .mega-dropdown-menu:before,
    .mega-dropdown-two .mega-dropdown-menu:after,
    .mega-dropdown-two .mega-dropdown-menu:before {
        display: none
    }
    .navbar-default .navbar-nav .open .dropdown-menu>li>a {
        color: #fff;
        text-align: center
    }
}

.mega-dropdown-menu {
    padding: 20px 0;
    width: 100%;
    box-shadow: none;
    -webkit-box-shadow: none
}

.mega-dropdown-one .mega-dropdown-menu:before {
    content: "";
    border-bottom: 15px solid #fff;
    border-right: 17px solid transparent;
    border-left: 17px solid transparent;
    position: absolute;
    top: -15px;
    left: 48%;
    z-index: 10
}

.mega-dropdown-one .mega-dropdown-menu:after {
    content: "";
    border-bottom: 17px solid #ccc;
    border-right: 19px solid transparent;
    border-left: 19px solid transparent;
    position: absolute;
    top: -17px;
    left: 48%;
    z-index: 8
}

.mega-dropdown-two .mega-dropdown-menu:before {
    content: "";
    border-bottom: 15px solid #fff;
    border-right: 17px solid transparent;
    border-left: 17px solid transparent;
    position: absolute;
    top: -15px;
    left: 82%;
    z-index: 10
}

.mega-dropdown-two .mega-dropdown-menu:after {
    content: "";
    border-bottom: 17px solid #ccc;
    border-right: 19px solid transparent;
    border-left: 19px solid transparent;
    position: absolute;
    top: -17px;
    left: 82%;
    z-index: 8
}

.mega-dropdown-menu>li>ul {
    padding: 0;
    margin: 0
}

.mega-dropdown-menu>li>ul>li {
    list-style: none
}

.mega-dropdown-menu>li>ul>li>a {
    display: block;
    padding: 3px 20px;
    clear: both;
    font-weight: 400;
    line-height: 1.428571429;
    color: #999;
    white-space: normal
}

.mega-dropdown-menu>li ul>li>a:focus,
.mega-dropdown-menu>li ul>li>a:hover {
    text-decoration: none;
    color: #444;
    background-color: #f5f5f5
}

.mega-dropdown-menu .dropdown-header {
    color: #428bca;
    font-size: 18px;
    font-weight: 700
}

.mega-dropdown-menu form {
    margin: 3px 20px
}

.mega-dropdown-menu .form-group {
    margin-bottom: 3px
}

@media (min-width:770px) {
    .dropdown-menu>li>a {
        text-align: center;
        background: #ededed;
        margin: 2px;
    }
}

    $(document).on('click', '.mega-dropdown-one', function(e) {
        e.stopPropagation()
    })
    $(document).on('click', '.mega-dropdown-two', function(e) {
        e.stopPropagation()
    })