To display your content on multiple subdomains, ensure that the UserGuiding Container code is installed on all of them.
Then, go to your content settings page and scroll down to the Page Targeting section.
Finally, set a targeting configuration that contains all subdomains.
Example [1]
AAA.mydomain.com/guide-page
BBB.mydomain.com/guide-page
Example [2]
https://prefix-AAA.mydomain.com/guide-page
https://prefix-BBB.mydomain.com/guide-page
That's all!
Remember to save and publish changes once you have finished with these settings. Your content will be displayed on all subdomains that match the Page Targeting.