How to execute the mapping condition

Dear All,

I have a scenario where the source and target mapping is as follows

Source                                          Target

HeaderNodeA                                 HeaderNodeB

Employeeid                                    EmpId

Employeename                              EmpName

Department                                    Dept

DateOfJoining                                 DOJ

If the Department value in incoming payload is 01 or 02 then the target node should not be created and an alert should be raised to end user. For rest of the incoming Department values, it should create the target node.

Please let me know how can i execute the above mapping condition.

Regards

Uday Kiran