I am traying to combine bootstrap-select and jquery chained to filter my select list. her is my code
<select id="mark" name="mark" class="selectpicker" multiple>
<option value="">--</option>
<option value="bmw">BMW</option>
<option value="audi">Audi</option>
</select>
<select id="series" name="series" class="selectpicker" multiple>
<option value="">--</option>
<option value="series-3" class="bmw">3 series</option>
<option value="series-5" class="bmw">5 series</option>
<option value="series-6" class="bmw">6 series</option>
<option value="a3" class="audi">A3</option>
<option value="a4" class="audi">A4</option>
<option value="a5" class="audi">A5</option>
</select>
When I choose BMW and AUDI. The only series that came up was for BMW. I am expecting BMW and AUDI series. here is jsfield sample https://jsfiddle.net/80zkodod/.