It is possible to define sharing and access control permissions for each data cube and dashboard.

This can be done from the Sharing tab of each. (Note: if you do not see the sharing tab it means you are not running in a user enabled mode).

Cube edit sharing

By default when you create a new (or duplicate an existing) data cube or dashboard the sharing permissions will be set such that everyone can view but only you can edit. These access permissions only apply to user level users, super-admin users can always view and edit all resources.

Cube edit sharing specific

It is possible to restrict access to only specific people.