I am the Product Manager for Postman Workspaces and wanted to address the feedback here. We removed the ability to share collections/environments between Workspaces. This was done as a result of feedback from customers, who had difficulty in managing their collections and maintaining a single source of truth. For example, since a collection could exist in multiple workspaces and can be edited instantly, customers found it hard to maintain tighter controls and ensure that a single edit doesn’t break their entire workflow.
As an alternative, you can fork an environment or collection to a different Workspace and also create a Pull Request to contribute changes back to the “Master” collection. We see this model as being a trade-off between enabling teams to have tighter controls on their Collections/Environments while also being able to collaborate.
However it is clear that there are things we can do to improve the experience further. We are planning for this and would like to get early feedback from folks on this thread.