How to add checkbox filter item after initialize jplist

I have 3 ajax that call curl from 3 different website.
When first ajax finish, I will initialize jplist and next ajax will add to the list.
The problem is I need to add item to checkbox filter from next ajax that is after initialize, so its means dynamic filter item.
Right now the working filter is the filter that come from first ajax.

How to add filter from next ajax after initialize?
The reason why after first ajax i do initialize is because i dont want user to wait until all ajax complete, because it will take time.

Thanks.