I am trying to create a multilevel dropdown, but it does not work for me, idk why. There is no error on my console. I am using Vuejs 2.version.

Here is my dropdown;

  <b-dropdown id="benutzer-dropdown" text="Benutzer" class="navbar-item">
    <b-dropdown-item href="/main/de/verwaltung/users/">Benutzer verwalten</b-dropdown-item>
    <b-dropdown-item href="/main/de/verwaltung/roles/">Rollen verwalten</b-dropdown-item>
    <b-dropdown-item href="/main/de/verwaltung/permissions/">Berechtigungen verwalten</b-dropdown-item>
    <b-dropdown id="submenu" right>
      <b-dropdown-item @click="handleSubMenuClick">1</b-dropdown-item>
      <b-dropdown-item @click="handleSubMenuClick">2</b-dropdown-item>
      <b-dropdown-item @click="handleSubMenuClick">3</b-dropdown-item>
    </b-dropdown>
  </b-dropdown>

and js function (I just wanted to test it, but there is nothing in my console)

  handleSubMenuClick(){
  console.log("clicked!!");
},