A user can have access through sharing to a tile-based dashboard, but NOT have permission to see all the tiles in the dashboard.
Each tile has a permission. The permission is set in Manage permission roles under reporting permissions. You will find the tiles in the list of Analytics tiles and standard dashboards.
This permission decides if a user has access to see a specific tile. If the user has access to see a tile, the user will see it everywhere it has been enabled. It is possible to share a tile-based dashboard with users but include tiles that they do not have permission to access.


