Class using:

<a class="btn-menu-mobile" href="javascript:;">
    <span></span>
    <span></span>
    <span></span>
</a>

<div class="t-mobile-menu">
    <div class="m-menu__title">
        <div class="title">Menu</div>
        <a href="javascript:;" class="m-menu-close">+</a>
    </div>
    <ul>
        <li class="has-submenu">
            <a href="#sub1">Tin tức</a>
                <span class="btn-toggle-sub"></span>
                <ul class="sub-menu">
                    <li class="has-submenu">
                        <a href="#">Tin tức 1</a>
                    </li>
                </ul>
            </a>
        </li>
    </ul>
</div>

JS using:

$(document).ready(function () {
    function closeMenu() {
        $('.t-mobile-menu').removeClass('show');
        $('.overlay-menu').removeClass('active');
    }
    $(".has-submenu > .btn-toggle-sub").on("click", function(e){
        var parentli = $(this).closest('li');
        if(parentli.hasClass('opened')) {
            parentli.removeClass('opened');
            parentli.find('> ul.sub-menu').slideUp(400);
        } else {
            parentli.addClass('opened');
            parentli.find('> ul.sub-menu').slideDown(400);
        }
        parentli.siblings('li').removeClass('opened');
        parentli.siblings('li').find('.has-submenu.opened').removeClass('opened');
        parentli.siblings('li').find('ul:visible').slideUp();
    })
    $('.btn-menu-mobile').on("click", function(){
        $('.overlay-menu').toggleClass("active");
        $(".t-mobile-menu").toggleClass("show");
        return false;
    })
    $('.overlay-menu, .m-menu-close').on("click", function(){
        closeMenu();
    })
});

SCSS:

/* CSS Menu mobile */
.t-mobile-menu {
    position: fixed;
    top: 0;
    bottom: 0;
    left: -85%;
    width: 85%;
    max-width: 400px;
    background-color: #f3f3f3;
    box-sizing: border-box;
    font-size: 14px;
    transition: 0.2s;
    overflow-y: auto;
    overflow-x: hidden;
    z-index: 999;

    &.show {
        left: 0;
    }

    .m-menu__title {
        position: relative;
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 12px 20px;
        border-bottom: 1px solid rgba(0, 0, 0, 0.1);
        color: rgba(0, 0, 0, 0.5);

        .title {
            font-size: 14px;
            margin: 0;
            text-align: center;
            width: 100%;
        }

        .m-menu-close {
            padding: 0;
            font-size: 26px;
            width: 26px;
            height: 26px;
            text-align: center;
            line-height: 22px;
            text-decoration: none;
            color: #111;
            transform: translateY(-50%) rotate(45deg);
            position: absolute;
            top: 50%;
            right: 8px;
        }
    }

    ul {
        margin: 0;
        padding-left: 0;

        li {
            position: relative;
            list-style-type: none;

            &.active > a {
                color: #00b140;
            }

            &.has-submenu a {
                padding-right: 35px;
            }

            & > a:before {
                content: "";
                border-bottom: 1px solid rgba(0, 0, 0, 0.1);
                display: block;
                position: absolute;
                left: 20px;
                right: 0;
                bottom: 0;
            }

            a {
                color: #000;
                text-decoration: none;
                display: block;
                padding: 11px 20px;
                transition: 0.2s;
                line-height: 1.3;
            }
        }
    }

    .has-submenu {
        &.opened > .btn-toggle-sub:before {
            content: "-";
        }

        & > a {
            position: relative;
        }
        & > .btn-toggle-sub {
            width: 40px;
            height: 42px;
            max-height: 100%;
            position: absolute;
            top: 0;
            right: 0;
            color: #000;
            z-index: 2;

            &:before {
                content: "+";
                width: 100%;
                height: 100%;
                display: flex;
                justify-content: center;
                align-items: center;
                transition: 0.2s;
                font-size: 18px;
            }
        }

        .sub-menu {
            padding-left: 20px;
            display: none;
            li {
                a {
                    font-size: 14px;
                }
            }
        }
    }
}

.overlay-menu.active {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    transition: 0.5s;
    z-index: 888;
}