Travel Mangement Workflow

Hi! Experts

I have a scenario like this. User1 has raised a travel request. 1st it will go to user2(Superior of User1) mail box. After approv by User2 mail will go to User3(Sanctioning authority) mail box. After approve by User3 mail will go to user1 that travel is approved and one copy go to the Admin dept for their information and necessary action.

After completion of the tour when final expenses will post by the user1 the same way it will go to user2 then to user3 and finally to Finance dept.

How to configure the travel Management Workflow to map the above scenario?

Thanks

BD