Adding checkbox for multiple selection in autocomplete

I am building an autocomplete with the help of jqueryUI. I want to add checkboxes to my array of data so that i can select multiple and they show in the filter field above seperated by commas.I have checked all over internet found few plugins but i want to create one by myself. for example i need to create something like this http://ift.tt/1oQkpAL. The third dropdown is how i want to make it and right now i m using http://ift.tt/V2Oe3H