Hi-- The legacy version used to have a setting for the number of copies to store in backup. Example 1 in your doc https://mspbackups.com/AP/Help/backup/about/retention-policy#ol describes a perfect solution for maintaining 1 full generation. What about two full generations?
The number of generations to store depends on full backup schedule and retention period. Check this forum thread where I explain how it works https://forum.msp360.com/discussion/9437/help-understanding-retention-policies