If you want to change what is displayed, you need to go to the appropriate entity and select Quick Find View.
Open it for editing.
You notice, that this view has the same three attributes as written above. The categorized search displays the first three attributes from this view. So if you want to change the results in categorized search, you need to modify these fields. Just click on the Add View Columns. Make changes, save and publish.
I hope this was helpful.
Have a great CRM!