When you have a Microsoft 365 tenant and an Azure Active Directory tenant, how can you give selected users access to a temporary Microsoft SharePoint document library?

Create Office 365 groups with expiration policy.

You can use wither

• Assigned membership type - you select users manually one by one
• Dynamic User membership type - you define matching users using a query.

With the increase in usage of Microsoft 365 groups and Microsoft Teams, administrators and users need a way to clean up unused groups and teams. A Microsoft 365 groups expiration policy can help remove inactive groups from the system and make things cleaner.

When a group expires, all of its associated services (the mailbox, Planner, SharePoint site, team, etc.) are also deleted.

When a group expires it is "soft-deleted" which means it can still be recovered for up to 30 days.