You can add custom subdomain (guides.mydomain.com) to the hub page. Let us learn how to link it. You will be adding a CNAME record to the domain DNS records
Go to Hub
Click Edit
Go to Settings
Find the Custom Domain section. You can read the instructions to set it up.
Enter the domain you want to link
Click Save and and add the CNAME record with value that is mentioned above, on your domain provider DNS records section.
Click Back
You can see the domain you have setup on the preview. Once the DNS configuration is done, navigate to this link to verify it is working
Wow, now the domain is linked to the hub page!