A typical scenario is described here:

https://octopus.com/docs/administration/authentication-providers/active-directory-authentication

(the diagram at the bottom with a one way trust)

Per my thread with Octopus support, Octopus will not respect group membership of DomainA. This would be useful where the resource domain is managed by one group but the user domain (DomainB) is a shared corporate resource.

Thank you for your time.