elementui dropdown实现二级菜单

<el-dropdown
        trigger="click"
        :hide-on-click="false"
        ref="dropdown"
        class="avatar-container right-menu-item hover-effect moredropdown"
      >
        <div class="avatar-wrapper" style="line-height: 40px;">
          {{(getCookie('ztName') ? getCookie('ztName') + ' - ' : '') + this.$store.state.user.name}}
          <i class="el-icon-arrow-down" />
        </div>
        <el-dropdown-menu
          slot="dropdown"
          :append-to-body="false"
          class="lang-select-dropdown"
        >
          <el-dropdown-item>
            <span style="display:block;">个人资料</span>
          </el-dropdown-item>
          <el-dropdown-item>
            <span style="display:block;">数据大屏</span>
          </el-dropdown-item>
          <el-dropdown-item>
            <el-dropdown
              :visible-arrow="false"
              width="200px"
              offset="100"
              :disabled="showDropdown"
            >
              <span class="el-dropdown-link">
                <i class="el-icon-arrow-left" />数据修复
              </span>
              <el-dropdown-menu
                :visible-arrow="false"
                class="lang-select-dropdown-chidren"
                slot="dropdown"
                :append-to-body="false"
                style="width: 100px;margin-left:20px;"
              >
                <el-dropdown-item>
                  修复所有商品转换率与库存
                </el-dropdown-item>
                <el-dropdown-item>
                  修复所有商品库存
                </el-dropdown-item>
              </el-dropdown-menu>
            </el-dropdown>
          </el-dropdown-item>
          <el-dropdown-item>
            <span style="display:block;">数据清理</span>
          </el-dropdown-item>
          <el-dropdown-item>
            <span style="display:block;">关于我们</span>
          </el-dropdown-item>
          <el-dropdown-item>
            <span style="display:block;">退出登录</span>
          </el-dropdown-item>
        </el-dropdown-menu>
      </el-dropdown>