Wolfram system modeler has a function called "equation browser", the youtube video here(at 20:58) gives an introduction about "equation browser", I am wondering if Dymola has the same function, it would be helpful to debug nonlinear system.
Also, it is welcome for some other workaround solution, like using python to visualize the equation structures.
Here is the screenshot of the "equation browser".
You can list the non-linear equation systems and their iteration variables (see the translation log), and you use the Plot Dependencies functionality to trace dependencies for a particular variable. Those are your best options at present.