removeRowGroup

removes one level of row grouping from the specified range

void removeRowGroup(number|array rowId,string page);

rowId	number\|array	optional, a row ID or a range of row IDs: [start, end]
page	string	optional, a page name

$$("ssheet").removeRowGroup();

Details

If the rowId parameter isn't specified, the method removes a grouping level from the selected row(s).

Ungrouping doesn't work with multiple active zones (multiselect).