Adobe Campaign Control Panel allows you to fully delegate a subdomain to Adobe Campaign.
Subdomain delegation from the Control Panel will be available in beta by the end of January, and subject to frequent updates and modifications without notice.
To access the Subdomain Management in Control Panel, go to:
Experience Cloud Home > Solution picker: Campaign > Control Panel card > Subdomains & Certificates card
Directly from the URL: https://experience.adobe.com/#/controlpanel/domain
The video below demonstrates how to delegate subdomains.