- Add Custom Post type (publications, events, causes, gallery and staff) to a specific category.
- Go to menu and create a new menu for ex: Publications by category and add the needed categories to it.
- Go to widget area and add "Custom menu" after that choose the menu you want to display.
Note*: If you don't see the categories section when you create the menu, go to "screen options" and add it. See attached image.