PKI Root CA with two different domains

Hi,

We currently have a PKI config. of 1 rootCA (offline) and two subordinate CAs within our staff domain (ie staff.domain.com)

We also have another domain that currently does not have PKI infrastructure, lets call this public.domain.com

Since the root CA is not domain joined and its offline, can I configure this in a way where the rootCA also signs the certificates for subordinate CAs in the public.domain.com, there is no trust between both domains and they are not in a forest.

So one root CA and two different domains.

thank you!