from my experience with (German) Inhouse Consultancies, Exits are typically into Senior or Project Management roles within the respective organization, in this case DHL. Some people might also exit externally, but often more attractive options evolve inside the organization as you can build up a network through various projects. Or, some might even exit to other (T1) consultancies ...
You can easily check linkedin to see the exits of different tenure levels at DHLC, usually (Sr) Consultants to Managers exit to (Project) Management positions, while (Sr.) Managers and above exit to "Head of/VP/..." positions.
Hope that helps,