My MEX functions look upwards in the subsystem heirarchy to get some information from top-level configuration blocks, which specify system wide parameters for my system. Normally I would find these with find_system(bdroot(gcb), ...).
But supposing I want to use model referencing. Is there any way a block in a referenced model can, during initialization of a system referencing it, find the top level of the referencing system? bdroot(gcb) will only get me to the top of the referenced model - not the active referencing model.