Hi,
You need to rely on something that remains constant even when the part file name is changed, so that you can still find the component you ae interested in.
If you override the component name in the model browser then that should remain constant even when the file name is changed.
So you could keep referring to it the same way instead of using the file name, e.g.:
Parameter("Level_1", "LevelHeight")
Cheers,
Adam Nagy
Autodesk Platform Services