Hello, Larry,
Thank you for writing to us.
Currently, the grouping functionality that is shown in the screencast is not supported in Flexmonster.
Instead, fields can be grouped into multi-level hierarchies via mapping.
To use multi-level hierarchies for the custom data source API, you need to handle certain request scenarios on your server. Please see the following guide for more details.
Please let us know if any additional questions arise.
Kind regards,
Vera