Can credentials from one tenancy be used to authenticate on another via define/admit policies?

Summary

Wanting to use credentials (user OCID, API key) on a remote tenancy by first creating policy in remote tenancy to allow external group to "manage"

Content

Here is my assumption:

The policy syntax whereby you can "define" an external tenancy and group then "admit"  that group to "read/use/manage" resources will allow me to use credentials from one tenancy to interact with resources on another tenancy.

Is the above possible?  If so can it be done through the OCI CLI built-in features or will this require raw API requests? Thank you for any guidance on this!

Jon-Eric
Mythics, Inc.