If u need that result ,u have to change the joins AS I mention in below

SELECT E1.Place, E1.Objective,E1.Year,E1.Month,E1.Exam1, E2.Exam2,E3.Exam3 FROM #tmpExam1 E1

LEFT JOIN #tmpExam2 E2 ON E2.Year = E1.Year and E2.Month = E1.Month and E1.Objective =E2.Objective

Inner JOIN #tmpExam3 E3 ON E3.Year = E1.Year and E3.Month = E2.Month and E1.Objective =E3.Objective

Group by E1.Place, E1.Objective,E1.Year,E1.Month,E1.Exam1, E2.Exam2,E3.Exam3