I use BitWarden quiet often and I have many websites running on my Servers where I have different logins.
So when I try to login on to my Roundcube instance located at mail.domain.tld the “Tab” section of the BitWarden extension shows me 11 entrys of domain.tld and not specifically mail.domain.tld.
Same for subfolders!
When I try to login on to my Admin GUI for Postfix located at mail.domain.tld/admin, the “Tab” section shows me all 11 entrys of this domain.
Therefore I think it should only show every entrys for the sub.domain.tld/subfolder
That is actually already possible and IMHO one of the best implementations among all the password managers I know.
There is a little cog besides the URL entries. There you have many different possibilities. For subdomain, you may choose the “server” rule. For the subfolder case I would use the “starts with” rule.
(I’m in the same boat and it works fine here :-))