Thanks Dave, I thought that might have been and out of the box page.
Whoever configured this in my organization has made it quite confusing. The menu item is called Resource Planning so I was quite surprised when I checked the group's instance rights and noticed it already had the following:
Page - View: Resource Planning
When configuring the Home menu I was able to find out that the page it links to is actually called Capacity. Adding the following right fixed the issue:
Page - View: Capacity