What is the concept of breadcrumbs for subentities?

Question

User interface

Abstract entities are given: “directory/file” (can be replaced with “music album/composition” or “series/episode”).
Structure url
"/files" list of all files
"/file/file_id" file
"/folders" list of all directories
"/folder/folder_id" directory
"/folder/folder_id/files" list of files in the directory
Address: "/file/file_id" , crumbs: "Files > file_id"
Address: "/folder/folder_id", crumbs: "Folder > folder_id"
________
Problem:
Being in the directory, the user sees a list of files, clicking, for example, on a file with id 64, it will go to the address "/file/64" (from the page "/folder/folder_id/files"). The structure is broken - there is no way to return to the previous directory by crumbs (before clicking "Folder> folder_id> Files" and after "Files> 64"). It would be more logical option "Folder> folder_id> Files> 64"
Option 1:
Leave as is.
Cons: described above
Option 2:
Going to the “/file/file_id” page (it doesn’t matter where), we check if the file is in any directory (yes, it may not be in the directory, don’t forget about the abstraction), if so , draw crumbs "Folder > folder_id > Files > file_id", if not, then "Files > file_id".
Cons: if the file is located in any of the directories, and the transition is made from the “/files” page, the hierarchy is again violated, since the crumbs will take the form “Folder> folder_id> Files> file_id”, going one level higher, the user will see a list of files in the directory, although it previously looked at the list of all files.
Option 3:
Add page "/folder/folder_id/files/file_id"
Pros: Hierarchy preserved
Cons:
# duplication of pages ("/file/file_id" and "/folder/folder_id/files/file_id" same page)
# long yurl
# it is not clear which of the addresses for ps to make the main: "/file/file_id or "/folder/folder_id/files/file_id". After going from the search engine to a specific file, if the user uses the crumbs, then it will be more useful for him to go to the list of files in the directory i.e. it is more logical to make "/folder/folder_id/files/file_id" the main address for ps, but if the file is not located in any of the directories, then the main address will be "/file/file_id". And again, some kind of architectural mistake, if today is Friday, then the main url is one, if Saturday, then another ... What would you do?
If someone is confused, try substituting the alternative entities suggested above.

Answer 1

1. There is a list of objects - these are structure objects.
2. There are objects with the "parent object" property - this is a structure (links).
3. There are filters (say, tags) by object properties.
You must decide: where you have and what.