Filter Category Select Drop down based on Another drop down option

I want to filter the list of options based on the selection of another drop down.

Please see the jquery code below; i am sure there is a tiny bit that i am missing that's why it is not working.

if($('#selectionone').is(':selected')){
    $('option').filter('.edibles');   

}
if($('selectiontwo').is(':selected')){
  $('option').filter('.vegfats');
}

Here is the jsfiddle link