/* Submenu rechts van parent (Bootstrap 3) */
.navbar-nav > li.dropdown > ul.dropdown-menu > li.dropdown-submenu > ul.dropdown-menu {
    position: absolute !important;
    top: 0 !important;
    left: 100% !important;  /* overschrijft Bootstrap left: 0 */
    z-index: 9999 !important;
    display: none; /* standaard verborgen */
}

.dropdown-submenu > ul.dropdown-menu {
    position: absolute !important;
    top: 50% !important;                /* midden van parent <li> */
    left: 100% !important;              /* rechts van parent */
    transform: translateY(+20%);        /* verticaal centreren */
    z-index: 9999 !important;
}

/* Hover/cursor */
.dropdown-submenu > a {
    cursor: pointer;
}

/* Show togglen */
.dropdown-menu.show {
    display: block !important;
}

/* Mobiel: submenu onder parent */
@media (max-width: 767px) {
    .dropdown-submenu > ul.dropdown-menu {
        top: 100% !important;
        left: 0 !important;
    }
}