I wasn’t actually meaning that the breadcrumbs ought to show hierarchies that come from outside the app, I was just meaning that there are occasions where the relationships even within the app can be multi-hierarchical and/or circular.
Take for example the fibery template for usability:
What should the breadcrumbs say for the Attempt entity?
Test → Participant → Attempt or Test → Task → Attempt ?
I actually have apps that are more complicated than this, and I know would not be able to have breadcrumbs shown in a meaningful way.
Perhaps the breadcrumbs implementation is wrong, perhaps the card needs to show a mini diagram of the app relationship diagram, with the entity type emphasised in some way (e.g. by ‘dimming’ the other ones):
