Separate Domain for Admin Pages

I want to achieve something similar to what asked in this thread: https://www.ads-software.com/support/topic/login-subdomain/. However, there are some differences.

I want the admin domain to host everything for administrating task such as login and content editing and let the other domain to be used for public users.

However, during the content creating in the admin domain, such as inserting images, WordPress stores the data inside the database as an absolute path, which includes the admin domain instead of the public domain.

Is there any way to make the content management utilize the public domain while still maintaining the use admin domain to access admin pages?

Thank you.