permissions in a knowledge base space

[Carla Norman]

I have a kb space connected to my service project.  I can restrict an article to only show to a group of users.  Can I set an article to serve to everyone EXCEPT a group of users?
Or can I target portal only accounts somehow? 
We have internal and external accounts.

[Aaron Geister_Sentify]

@Carla Norman 

I hope you are doing well. In my experience when we had internal documents and external documents I would add two spaces. One for customer or external and one for internal. This way you can adjust the permission from the linked confluence space. 

Those options are there when you link or create a space from with the JSM project setting Knowledge Base options. 
If you link multiple confluence kb spaces you can then edit the permissions here. Who can view for public customers should be set to "any logged users" and then who can edit would be "Service Desk users" 
When you link the second space for internal you can set them to only confluence users for both options. That should make what is available at the portal for different users.