Currently, to resolve a path of id_shorts of Referable objects, we need to chain the get_referable-function:

submodel.get_referable("foo").get_referable("bar")

It would be sensible to add a convinience function to resolve the id_short path (foo/bar) with one call.
(However, please double-check how the specification defines the id_short path and use this to implement our path resolving)