It depends on which subscription you have. Employees or Core Users with the HR Standard subscription can view their own HR information only. You are able to see your reviews, even if they are not marked as completed. This subscription provides read-only access.
Typically, you should also add the Time & Expense subscription package alongside HR Standard, so that the employees can request time off in addition to making time and expense entries. If you want them to have full access to all Core HR features, you should use the HR Administrator subscription instead.