<select data-mdb-select-init id="selectID">

  <option value="-1">All</option>

  <option value="2">Two</option>

  <option value="3">Three</option>

  <option value="4">Four</option>

  <option value="5">Five</option>

</select>

<label class="form-label select-label">Example label</label>

​

<a href="" onclick="return false;" id="setToFirstValue" class="icon-link">set me To "-1"</a>

<a href="" onclick="return false;" id="setToLastValue" class="icon-link">set me To "5"</a>

​

let select = document.getElementById("selectID");

let selectInstance = mdb.Select.getOrCreateInstance(select)

selectInstance.setValue("2");

​

document.querySelector("#setToFirstValue").addEventListener('click', () => {

    selectInstance.setValue("-1");

});

document.querySelector("#setToLastValue").addEventListener('click', () => {

    selectInstance.setValue("5");

});