As a Global Administrator in Azure Active Directory (Azure AD), you might not have access to all subscriptions and management groups in your directory.
f you are a Global Administrator, there might be times when you want to do the following actions:
Regain access to an Azure subscription or management group when a user has lost access
Grant another user or yourself access to an Azure subscription or management group
See all Azure subscriptions or management groups in an organization
Allow an automation app (such as an invoicing or auditing app) to access all Azure subscriptions or management groups.
Please into Elevate access for a Global Administrator here:
https://learn.microsoft.com/es-es/azure/role-based-access-control/elevate-access-global-admin