Simulation of transaction level models (TLMs) is an established embedded systems design technique. Its use cases include virtual prototyping for early software development, platform simulation for design space exploration, and reference modelling for verification. The different use cases mandate different trade-offs between simulation performance and accuracy. Therefore, multiple TLM abstraction layers have been defined of which one has to be chosen and integrated into the system model prior to simulation. In this contribution we present a modelling technique that allows covering several layers in a single model and switching between the layers at any time, in particular dynamically during simulation. This feature is employed to automatically adapt simulation accuracy to an appropriate level depending on the model's state, leading to an improved trade-off between simulation performance and accuracy.