From the calendar window, click “File” (1).
This takes you to the “Info” section (1). Choose “Options” (2).
Select “Calendar” (1). Click on “Free/Busy Options…” button (2).
Choose “Permissions” tab (1). NOTE: “Permission Level” is most likely currently set as “Free/Busy time” (2).
Under “Permissions” section, select the drop-down arrow next to “Permission Level:” (3). Choose “Reviewer” (4), or whichever level you wish to grant. You can make any tweaks and they will be saved as “Custom” if they don’t already have a level template. Click “Apply” (5).
Now you will see that “Amber” is listed as “Reviewer” (1), having “Read” | “Full Details” (2), and “Other” | “Folder visible” (3). Once you verify this is what you want, click “OK” (4).