This advance filter use the option feature so that you can add as many filter option as you want

Features:
- No file override (VQmod)
- Optional to use price range
- easy to use. Will help to install if you want for free
- Only available for category page

Demo:

Frontend: http://indomobilrental.com/opencart-1.5.6.4

Backend: http://indomobilrental.com/opencart-1.5.6.4/admin
username: demo
password: demo