This field allows to display if the user of the item belongs to a group (will display Yes or No) or to display since when he is in the group
The parameter contains
- the name of the group
- eventually the string 'date'
To work the tracker must have a field of type user selector with option 1 (creator).
For instance, you can use that field in a tracker, and then request with a PluginTrackerList to list all records from a user tracker which belong to a specific group, and show all their details: phone, address, etc.
See also: User Groups tracker field, which is more powerful.