title: I have a multi select vue element broken down by groups and want to limit the users selection by group
body: <p>I am new to vue so I'm not sure if this is a simple or hard question; but I have two groups one is for clients and one is for departments, I would like the user to be able to select one client and one department only.Any help would be great</p>
  <pre><code> &lt;el-select v-model=&quot;value&quot; multiple filterable placeholder=&quot;Filters&quot; &gt;
    &lt;el-option-group
        v-for=&quot;group in options&quot;
        :key=&quot;group.label&quot;
        :label=&quot;group.label&quot;&gt;
      &lt;el-option
          v-for=&quot;item in group.options&quot;
          :key=&quot;item.value&quot;
          :label=&quot;item.label&quot;
          :value=&quot;item.value&quot;&gt;
      &lt;/el-option&gt;
    &lt;/el-option-group&gt;
  &lt;/el-select&gt;
  </code></pre>