Hello Bentley,
This is a new Place Cell Feature to create Compound Cells on the fly.
With a new Place Cell palette, the user has most of the existing Cell Properties available to enable or modify, but this tool simultaneously opens the Cell Library dialog box in a multi-select mode' where the user can select all the Cells to place.
The user can choose a master Cell or let the tool do that automatically by using library selection order.
On the tool palette the user my type a name or choose to inherit a name from the Cells, or maybe ever a lookup table or Item Type name to apply.
When place, all the Cells are place in the Design based on their origin, but as a single compound Cell which still retains the Cell structure.
In the tool palette the user can choose to drop the structure.
To take it a step further, if Cells have multiple placement points, they can choose one of the alternate placement points by clicking on the point in the Cell preview.
The image attached is the existing Place Cell tool palette.
The Compound Cell placement palette would have additional controls as described above.
[The palette could even include the option to add the new nested Cell to the attached Cell Library.]
Link these two ideas as an implementation: