Simple Powershell script to list all user groups including groups in trussing domains and forests
.\get-AllUserGroups.ps1 <object(user,group,computer,...) samaccountname> <object fqdn domain name>
Four colomns separated by TAB are sent to the stadard output, it can be redirected to a file and opened by Excel
|<Object>|<Group>|<how the user is nested in the group>|<how many times the object is directly or indirectly member of the group>