How do i populate bootstrap tokenfield ,based on which input field i am focus on

Question

I have these three 'tokenfields' and a list of checkboxes email ids . i manage to add email id to the first tokenfield that is "tokenfield-1".

<div class="form-group usersEmailList">
 <div class="tokenfield input-group">
          <span class="input-group-addon">To:</span>
           <input type="text" class="form-control usersEmailId" name="mailTo" id="tokenfield-1" data-tokens="" />
  </div>
</div>
<div class="form-group usersEmailList">
 <div class="tokenfield input-group">
          <span class="input-group-addon">Cc:</span>
          <input type="text" id="tokenfield-2" name="mailCC" data-tokens="" class="form-control CC">
  </div>
</div>
<div class="form-group usersEmailList">
 <div class="tokenfield input-group">
          <span class="input-group-addon">Bcc:</span>
          <input type="text" id="tokenfield-3" name="mailBcc" data-tokens="" class="form-control">
  </div>
</div>

what i manage to do so far

$("#list").on('change','input',function(){
       var dataCheck =  $(this).val();
        if($(this).is(':checked')){

         arr[count++] = $(this).val();

         $('#tokenfield-1').tokenfield('setTokens', arr);
        }else{
        alert(arr);
        $.each(arr,function(i){
           console.log(dataCheck);
           if(dataCheck == arr[i]){
           arr[i] ="";
           }
          /* console.log(arr[i]);*/
        })
         count--;
         addMailId(arr); 
        }


    });

How do i set SetToken to the 2nd tokenfield-2 if i select select from the same list of checkboxes,is there a way where it knows that the tokenfield-2 is focus .I tried

$('#tokenfield-2').focus(function(){
});

i cannot get it to focus ,or find a way to somehow focus on tokenfield-2