SELECT *
FROM tbl_calendar t1
INNER JOIN tbl_citydepartmentoffice t2 ON t1.id_cityDepartmentOffice=t2.Id_cityDeparmentOffice
INNER JOIN tbl_schedule t3 ON t2.id_department = t3.id_department
INNER JOIN (SELECT A.Date,B.id_office,B.id_department
                  FROM tbl_schedule A
                  INNER JOIN tbl_citydepartmentoffice B ON B.id_department=A.id_department
                  WHERE A.id_employees=1001)
tt ON tt.Date=t3.Date AND tt.id_department=t2.id_department AND tt.id_office=t2.id_office