Subcategory in Autodesk Platform Services PropertyPanel

based on the tutorial on the APS website I created an extension with a panel. The panel is a PropertyPanel (like summary extension) and will be generated automaticly through some loops. My Question is: With the command .addProperty(name, value, category) I will create a new line in the panel. Is there a similar command availible the get a list, like

?
With the regular command there will be only

• • 2.2.
    two levels possible.

Thanks

I was just trying to put the subcategory in the third parameter or put another command in the third parameter, but nothing happend that I search/expect. Also some searches in the web are unsuccesfull.