Adaptive Scopes

EzeTech​  The adaptive scope will gradually populate over several days, so even though you see some users in the list now, it may not have fully populated. I have even seen it take more than a week to fully populate. over a week. You can now use PowerShell Get-AdaptiveScopeMembers (ExchangePowerShell) | Microsoft Learn to list the members in a specific adaptive scope. This is worth cross-checking against the list of users you expect to be in the scope. 

For Microsoft 365 (Entra Groups) you can use the following properties to build your Adaptive scope queries. 

• Name
• Display name
• Description
• Email addresses
• Alias
• Exchange custom attributes: CustomAttribute1 - CustomAttribute15
• Exchange extension custom attributes: Extension Custom Attribute 1 - Extension Custom Attribute 5

I always try to avoid using Display Name as even with a defined provisioning process that adds prefixes (e.g., HR-GroupName), owners can change the Display Name at any time. Instead, use custom attributes, as users cannot modify these values. If you have a provisioning process, you can write the value (e.g., HR) to the relevant custom attribute after the group has been created.

As you mentioned, the Adaptive Scopes can take some time to populate, so I recommend testing the query using Exchange Online PowerShell and applying the appropriate filter e.g. Groups starting with SAM.

Get-Recipient -RecipientTypeDetails GroupMailbox -Filter {DisplayName -like "SAM*"}

This way you get to see what groups will appear in the Adaptive scope. If you need more details, please share your query and what you want to include in the scope. 

Reference

Adaptive scopes | Microsoft Learn