Box 1: 2 -
One management group for each Azure AD tenant
Azure management groups provide a level of scope above subscriptions.
All subscriptions within a management group automatically inherit the conditions applied to the management group.
All subscriptions within a single management group must trust the same Azure Active Directory tenant.
Box 2: 1 -
One single blueprint definition can be assigned to different existing management groups or subscriptions.
When creating a blueprint definition, you'll define where the blueprint is saved. Blueprints can be saved to a management group or subscription that you have
Contributor access to. If the location is a management group, the blueprint is available to assign to any child subscription of that management group.
Box 3: 2 -
Blueprint assignment -
Each Published Version of a blueprint can be assigned (with a max name length of 90 characters) to an existing management group or subscription.
Assigning a blueprint definition to a management group means the assignment object exists at the management group. The deployment of artifacts still targets a subscription.
Reference:
https://docs.microsoft.com/en-us/azure/governance/management-groups/overview
https://docs.microsoft.com/en-us/azure/governance/blueprints/overview
