how to add topics in extra pages

i made a forum for a college n made 3 pages in it. i.e. a general page, which default and a page each for students and teachers. now i want to add categories and topics seperately for each page. the categories i create from admn panel comes only in default page. how can i add topics in other two. i want to manage the other two pages individualy. i made buttons to redirect to that page in header. bt dnt knw hw to add topics in that.
pls help me...

Go to "Display / Structure & Hierarchy" and choose another index packing there - one of the three "split categories on index" options should do the job.