Visibility & access to sub items on parent item

When opening a subitem, there is a link to the parent item on the top left, which is great for getting access to the overall context of a task.

However, there is no link or visibility on a parent item of any subitems, which breaks the chain.
It would be best to have a new tab next to “Files” that shows “Subitems” if Subitems are added to a parent item.

Otherwise, how are people managing access between parent and sub item? Copying and pasting sub item links into the parent item? Going to the specific board, finding the task, opening the drop down for sub items?