.dropdown-menu .dropdown-submenu .dropdown-menu{
    display: none !important;
}
.dropdown-menu .dropdown-submenu:hover .dropdown-menu,
.dropdown-menu .dropdown-submenu:focus .dropdown-menu{
    display: block !important;
    margin-left:100%;
    margin-top:-38px;
}

#menu-header .menu-item:nth-last-child(1) .dropdown-menu .dropdown-submenu:hover .dropdown-menu,
#menu-header .menu-item:nth-last-child(2) .dropdown-menu .dropdown-submenu:hover .dropdown-menu,
#menu-header .menu-item:nth-last-child(3) .dropdown-menu .dropdown-submenu:hover .dropdown-menu{
    margin-right:0;
    right: 100%;
}
@media (max-width:991px){
    .dropdown-menu .dropdown-submenu:hover .dropdown-menu,
    .dropdown-menu .dropdown-submenu:focus .dropdown-menu{
        margin-left:0;
        margin-top:0;
    }
}