wordpress - convert combo list to checklist with multiple choice

Avg Bid (USD)
Project Budget (USD)
$10 - $30

Project Description:
i have a combo list that filter search in custom categories.
i want to convert it to checklist with multiple choice option.
its should be responsive and dynamic.
if i add category or subcategory - it should appear in the list automatically.
the category should appear in bold and the subcategory in regular.
if the user select category - all the subcategories will be checked automatically . the user can deselect or select any option he wants.
there will be option to select all or none.
all the choices the user made should use for the search .

Skills required:
AJAX, jQuery / Prototype, PHP, Software Architecture, Wordpress
About the employer:
Public Clarification Board
Bids are hidden by the project creator. Log in as the employer to view bids or to bid on this project.
You will not be able to bid on this project if you are not qualified in one of the job categories. To see your qualifications click here.

$ 54
in 5 days
$ 54
in 3 days
$ 53
in 3 days
$ 54
in 3 days
$ 25
in 3 days
$ 25
in 3 days
Hire brij420
$ 30
in 1 days
Hire claudinemalo16
$ 25
in 3 days
Hire adrianaudi
$ 25
in 6 days