For most standard reports of the system, developers have implemented the ability to set fields by which data in the report will be grouped. Predefined groupings are available to the user in the Quick Settings panel:
In defaultGroup by section user may select attributes which would be used for groupping data in report and aslo user may set order of grouppings (move them using the up and down arrows 
.
Grouping of data in the report by selected fields will be applied in the order in which they are located in the Group by section.
In case when user need to add additional grouppings in report - he may use Change report Variant option (menu More Actions - Change Report variant):
For making setting about groupping it is needed to open Groupping Fields tab and due to report structure level (upper area) it is possible to add/change grouppings.
For example, in the inventory balance report you need to add a grouping by the folder in which the item is located.
How this can be done in the system:
Open Change report variant on Groupping fields tab.
As we can understand - this groupping should be used upper than Item - so we need to highlight upper level than Item (in Balance of Inventory - it is Warehouse level) and push Add - new groupping.
On groupping fields tab it is possible to edit new groupping and select type of groupping - Elements, Hierarchy, Hierarchy only:
Please note that when you add a new report grouping, it appears not only on the Grouping Fields tab, but also in the Report structure. And user may edit it in both areas.
After saving the described settings, the report will be generated as follows: in report form Item.Folder was added and it was also added into Group by section on Quick Settings panel.
The user can save their settings as a new report variant for later use.