About Dynamic Objects in Access Control Rules
You can use dynamic objects on the access control rule's Dynamic Attributes tab page, similarly to the way you used Security Group Tags (SGTs). You can add dynamic objects as source or destination attributes; for example, in an access control block rule, you can add a Finance dynamic object as a destination attribute to block access to Finance servers by whatever objects match the other criteria in the rule.
You cannot create dynamic attributes filters for GitHub, Office 365, or Azure Service Tags. These types of cloud objects provide their own IP addresses.