This filter allows the use of wildcards to import users from specific Azure AD groups which names contain specific text strings.
Examples:
The below filter import users from Azure AD groups with names starting with "AzureAD"
^AzureAD.*
with "AzureAD" in the middle of the name
.*AzureAD.*
.*AzureAD$
Reference:
https://docs.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-language-quick-reference