Need Help In Sql Filter Query

Question

I Have 3 Dropdwon Branch,department,level And i Want to filter record according to these 3 parameters all parameters is nullable 

 

my query is

 

SELECT e.EmployeeID,e.LevelID,e.EmployeeCode,e.EmailID,e.MobileNo,e.BranchID,e.DepartmentID,e.EmployeeName,

b.BranchName,d.DepartmentName FROM EMPLOYEE e

LEFT OUTER JOIN Department d ON d.DepartmentID=e.DepartmentID

LEFT OUTER JOIN Branch b ON b.BranchID=e.BranchID

WHERE e.IsDeleted<>1 AND @BranchID IS Null or e.BranchID=@BranchID AND @DepartmentID IS NULL OR

e.DepartmentID=@DepartmentID AND @LevelID IS NULL OR e.LevelID=@LevelID

   

 

Pls Help Me