Smart Group for duplicates missing

After syncing a database I noticed that there are a lot of duplicates in this database. For some reason this same database has no smart group folder of duplicates.

How do I create a smart group folder for duplicates using smart group editor?

Click Data > New > SmartGroup in the menu bar. When the Smart Group is created it will open to ask to set it up. Use these settings:

to add that second parameter (“Instance is”) after you enter the first one, click the plus sign on the right side and you’ll get a new line to configure.

Select Data > New > Smart Group and add criteria of Instance is Duplicate.