How can we create multiselect using Angularjs?

Question

I have single select using AngularJs ng-options that is working good but my requirement is to make multiselect using AngularJs , How can i achieve that task using ng-options ?

main.html

    <div class="row">
    <div class="form-group col-md-12 fieldHeight">
        <label for="originatingGroup" class="required col-md-4">Originating group:</label>
            <div class="col-md-8" disable-control-point="CHALLENGES_EDIT">
                <select
                   class="form-control"
                   name="OriginatingGrp"
                   id="OriginatingGrp"
                   ng-model="challengesDTO.originatingGrpLkupCode"
                   ng-options="OriginatingGroupOption.id as OriginatingGroupOption.text for OriginatingGroupOption in challengeGroupOptions">
                   <option value="">
                     Select...
                   </option>             
               </select>
            </div>
    </div>
</div>

Answer 1

Just add "multiple"

            <select multiple
               class="form-control"
               name="OriginatingGrp"
               id="OriginatingGrp"
               ng-model="challengesDTO.originatingGrpLkupCode"
               ng-options="OriginatingGroupOption.id as OriginatingGroupOption.text for OriginatingGroupOption in challengeGroupOptions">
               <option value="">
                 Select...
               </option>             
           </select>

challengesDTO.originatingGrpLkupCode must and will be an array