Login to the Azure AD Tenant with no Azure Subscription. Create a lot of Azure AD Groups and add a user as member to them. This can be used to test Azure AD authentication for scenarios when a lot of Groups are send by Claims

CreateAmountOfGroups.ps1

$userId = "<ObjectID of AAD User>"
$countOfGroupsToCreate = 300
$groupNamePrefix = "testgroup"
for ($i = 0; $i -lt $countOfGroupsToCreate; $i++)
{
    $newGroup = (az ad group create --display-name "$groupNamePrefix-group$i" --mail-nickname "$groupNamePrefix-group$i" -o json) | ConvertFrom-Json
    az ad group member add --group $newGroup.Id --member-id $userId
}

loginToTenant.ps1

az login --tenant testtenant.onmicrosoft.com --allow-no-subscriptions