<div class="field">
                        <label>Objectif</label>
                        <select name="skills[]" class="ui fluid multiple selection dropdown" id="multi-select">
                            <option  *ngFor="let objectif of listObjectif" selected [value]="objectif.id_obj">{{objectif.des_obj}}
                            </option>
                        </select>
                    </div>
                </div>

/*to enable multiple select */
        this.selectedObjectif = $('.multiple.selection.dropdown').dropdown('get value');

       /**Just test an example then pass the list**/
        var values = 'Test,Prof,Off';
        $('#multi-select').val(values.split(','));