For the past upteen years, to get a list of the groups a user belongs to, I’ve used:
> net user /domain userID
Today, I just stumbled upon a powershell cmdlet that does just that.
To get a list of groups a users belongs to run the following at a powershell prompt.
PS c:\ >Get-ADPrincipalGroupMembership userID | select name
Note: You will need the Active Directory Powershell module and that comes from installing RSAT.