View Parent and Child together in "Category"

Hello All,

So on my helpdesk I have a large list of ticket categories and many sub-categories to them. Now the subcategories do repeat themselves in the various categories. When I open up a ticket the top line that displays the category will show for example 'Other' and not Printer\Other or Communication\Other. This also makes reporting a bit hard too because if I want to see all Printer related issues I have to select all the subcategories in the printer category.

Is there a way to display this and have reporting also pick the category in a filter? Is there a clever trick around this maybe? I also tried using Custom Fields but that means the subcategories cant be linked to categories as Custom Fields types are only text, numbers, drop down, Boolean and no option for a tree or relational list.

I am new to the product and need some help understanding the concept and limitations.

Thanks in advance.