Allowing non members of a workspace to view the contents (preview) of a linked related item

We have multiple UK partners that need to work together in certain workspaces and need to see the preview contents of each others linked opportunities and other cases in order to work efficiently but not have access to these linked cases. At the moment non members of a workspace will see the linked case as shown below)

But we need them to see this view below so they can see who is dealing and what stage the opp is at etc.

To be able to customise in the reference layout (see below) what workspaces can see the preview contents (but not access the linked items) would allow our partner to do their work effectively which they cannot do at the moment.