Hello, if I understand well your question: yes it is possible... but It could be complicated in the long run!
It depends of your Information Barriers segments architecture and the different levels of communication your want to implement.

For your case, you would need to create several segments:
- Segment1: User A => blocked with Segment4
- Segment2: User B => blocked with Segment3
- Segment3: Guest 01 and Guest 02 => blocked with Segment1
- Segment4: Guest 03 and Guest 04 => blocked with Segment2

I gave a similar example in an article I recently wrote on the topic: https://www.thijoubert.com/2021-07/InformationBarriers-Feedback-from-the-field-1-2/

Let me know if it answers to your need.
Best regards
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