Customize opencart module

Hello everyone i was customizing a opencart module whitch is a filter and i hire a freelance developer but i need a few more things whitch he says are possible but he never replay me after this and i need it to be done so im looking for another freelancer ready for this job and + more after this. The filter works with options but i needed to use categories too so the programer who i hired done this but i need to separate them on 4-5 or even better if i can add from admin panel as much as i want but thats optional ( now i have all categories in one place) . here is the website filter : [login to view URL]оферти The filter works with multi select so must stay that way.