It can be done. The way I would approach it is to have a series of tick boxes against each category that says who should see each entry. Then write a series of filters against the category object which just lists the ones you want people to see, so a filter called IT, one called technical. Then put a series of conditional filters in object designer against the category object held on the incident process which looks at the group and says show this filter, for the next group show the other filter and so on. Try to make sure only one filter will ever get fire off in the set of conditions.
That should do it.
However if you are new to LD, that isn't the easiest of things to do, so you might consider a boot camp course or asking whoever did the implementation for you to provide a bit of initial help