Drill in place breadcrumb
Drill in place shows a small arrow to go back, to increase usability by showing a bread crumb that allows navigating more than one level, just like normal drill-downs on a full view of the card.
It stands to reason that some the card titles will be long and will make the breadcrumb too big and not functional, I think that's fixable by having the links with a max-width and text truncation except for the current drill path card title.
Main card with a Summary > Secondary Card Showing Revenue > 3rd card with a very important level of granularity => Main card w... > Secondary Card.... > 3rd card with a very important level of granularity
Hovering over the truncated links will tell you the full title.