Topology optimization methods for continuum systems (structural topology, shape, material) are well-established. However, these methods do not apply to non-continuum or dynamic systems with discrete components with unique characteristics as with hybrid vehicles. This chapter examines the power train topology and control design optimization problem at vehicle system level. The design space related to power train and control system optimization level is rapidly increasing with new developments in power train, auxiliary technologies, system architectures (topologies) and cyber-physical systems. The multi-objective, mixed or hybrid (continuous/discrete time) character on both coupled levels of the problem requires relative long computation time. Therefore, it requires a bi-level (nested) or simultaneous system design approach. Since, sequential or iterative design procedures fail to prove system-level optimality. In this chapter, some illustrative examples are discussed related to nested control and design optimization problems related to continuous/stepped-gear transmission shifting, power split control and/or in combination with topology optimization.