Indicating selection in a list with sub-levels not always visible

Suppose we perform a search on an object name and get this results list:

enter image description here

From this list exactly one element can be selected in order to perform an action on that element. An element can be either:

  • An object itself
  • OR an item connected to an object
  • OR a part connected to an object

An object can have zero or more items and zero or more parts. Items (of which there may be many) is listed in a separate dialog. Parts (of which, often there is only a few) could be listed on inline expansion. The following image shows this setup:

enter image description here

My question is this:

  • How to best indicate a selected element if the list in which it appears is not always visible?

I know a general solution to showing a selection in a list would be a dropdown/combobox. However, I think this kind of control bloats the UI in this case and has an affordance more like “required” than “optional”. Also, it’s not very good in terms of interaction in case of long lists (with a lot of scrolling).

My best bet at the moment would be to use color if one of the items or one of the parts is selected. For parts it would look something like this:

enter image description here

This, however, is an inconcise and not so elegant solution. Do you have any better suggestions?