Multiple companies w/ shared database + different domain URL + different apps

I have set up two daughter companies to a single mother company from ERPNext → Company → added two more under the mother company’s group.

Now, I wonder if I can give different URLs w/ different login page design to each daughter. By the permissions, I can see that I can control what a daughter company’s employee can see, so assigning different apps’ functions on the same database does not seem impossible. (although it may require some extra work on in-system rule settings).

As long as I can give different web design for each daughter companies w/ corresponding URL, I think I can settle.

And it might be related to above question that I want to assign a new domain to wiki module, wiki.example.com, and available for all non-logged in users so that it can serve as a document set for instructions. The structre, at least to me, is similar to above. Database is shared with the mother site, but domain URL is different, and only wiki module is available on that domain URL.

Essentially, all these will create a network of websites from a single database, but different URLs + apps.