The Form's source is here .

How to import Form into the system see here . 

Create and save a new form

Launch an XLSX Workbench, and create a new form with name SUBTOTALS .

Assign a context to the form 

Assign a context ZCONTEXT_SUBTOTALS to the form. When an automatically creation of the Form structure will be prompted, you should press the button 

in order to create a structure manually.

Markup of template 

Markup an Excel-template as shown below :

 Create a Form structure

Add the new components into form structure as shown in the picture below:

Template binding for components

Perform Template binding for all the «Patterns» and all the «Values» according to scheme below:

Context binding for components

Perform Context binding for «Loopsteps» and «Values» according to scheme below:

Activate the Form by pressing a button 

Explanations

«Folder» components are needed in the Form structure just for setting up collapsible rows for the list levels. Pay your attention to option «Group» in the properties tab of the «Folder» :