How to give access to your DFS(Distributed File System) from another domain?

Question

Distributed File System

Greetings colleagues.
There is domain #1 in which DFS of the type \\#1\namespaces is successfully deployed
. There is also domain #2, and an unbridled desire to give its users the opportunity to use file balls from the first domain, through DFS, that is, from the second domain, a link of the form \ \#1\namespaces also worked, albeit with a login and password request.
Has anyone faced such a problem?

PS There is no trust relationship between domains.