Any guidance would be appreciate. Maybe I am not setting up this correctly, or maybe just known limitations. I have One Customer Group. I have one Item Collection with all items except one. I have that single item in its own collection. In theory, I assume this screenshot should disable all purchasing and pricing for all items except one. (This doesn't happen, I can buy and purchase everything as the Test Customer Group).

@AnaFarms cuz the test customer group is also involved in above segment?

It is involved as "disable purchase and hide price".

I think you should try by first removing the "All Users" groups from your mapping. Giving all users full permissions and then trying to set up an exclusion with a separate group (when members of that group are contained within "all users") is probably the cause

@Steve Goldberg How can I say for "All Items Except Test Item" I want every visitor to see these EXCEPT "Test Customer Group". That doesn't seem possible with Segment Manager? Almost as if NetSuite needs one extra layer of logic customization?

I'm pretty sure if you remove the ALL USERS mappings and just leave "Disable Purchase and Hide Price" : "Test Customer Group" it would achieve what you want

Removing all users does resolve the issue for Test Customer Group. However, Customer Segment Manager cannot handle logic such as "All Items Except Test Item" I want every visitor to see these EXCEPT "Test Customer Group". All of the generalized segments (ALL USERS, ANON USERS, LOGGED AND RECOGNIZED) override a specific customer group. Any items duplicated across two collections will also run into that issue. I think NetSuite needs NOT logic to this, in order to fully the rules fully usable.