You can give visibility to other users on someone else's review by clicking on the + next to the eye. They will have a read only access.
On Performance > Review, click on the three dots at the end of the line and select Edit participants.
In the panel, click on + Add a viewer.
Start typing the first letters of the viewer and select them in the drop-down menu.
Once they have been added as a viewer, users can access Reviews in the Reviewer only tab.
Note: Only the person who started the campaign is authorized to intervene on sharing an interview.