Context needs to be preserved when navigating through a hierarchical or tree-like structure of content where the content itself takes the most visual precedence.
The cardinality of the content hierarchy is often hard to estimate because it depends on how the customer or user has set up the application based on their specific environment.
The hierarchy could be deep or wide, and may not always be balanced.
Context must always be visible to the user does not get confused as to how they navigated to the current page.
This also helps when working as a team, one user needs to communicate with another user, the context they are observing or experiencing an issue in.
As a navigational tool, the user should be able to jump back to a previously traversed part of the content hierarchy without needing to use the “back” browser interaction multiple times.
In a more advanced scenario, the user should also be able to open a sibling node of a previously traversed part of the content tree and start traversing a different branch.
The breadcrumb UI should be seen visually above the content it references to.
The individual parts should look clickable to allow for jump-navigating backward.
If allowing alternate branch traversal, the affordance should indicate that it is permitted and the interaction should be separate from that allowing a simple jump to a previous context.
There should also be an easy way to show which node is selected, and filter the list of sibling nodes to allow easy finding.
Overflow patterns should be gracefully handled. Especially if a page was opened with a large contextual navigation without the user actually navigation through it (eg: L1 operator shares a link to a problem with the app owner with context already traversed).