This feature is currently not available.
Right now you can either use the categories or turn it off completely.
But you can mute (deactivate) single categories, you do not want to use:
- On iOS: 'Settings' > 'Categories & Tags' > Swipe to the left on the tag and click on 'Mute'
- On macOS: 'Manage' > 'Categories & Tags' > 'remove checkmark from the tag'