In a WF .how to navigate to PurchaseTab view using Material master Creation

User will enter data in MM01 (material creation) in basic data1 and basic data2

2) now a mail should be triggered to person responsible for Purchasing dept

3) once he(pur dept) approves the request of material creation, it should navigate him to material master purchasing tab.

How to navigate to Purchasing tab..could you please slove this probles