What items should be displayed in the calendar?
If you want to show the projects of the employee, then just add the calendar widget directly in the dataview connected to Employee and constrain your data over the association Project_Employee
It looks like you are showing the calendar for each project of the selected employee. I guess you only want to show one calendar per employee and show the projects on the calendar. To achieve this, you first need to place the calendar widget inside of the dataview that is showing your employee.