Grouping allows to divide listing items in groups designated by expression value. For example we can group goods by the amount of VAT associated with it.
put cursor in listing on an expression by which you want to group
choose from popup menu
>or choose from menu
> >Grouping by a relation allows dividing listing item in groups designated by their own relation.
put cursor in relation by which you want to group
choose from popup menu
>or choose from menu
> >If grouping was the last made operation just undo it.
Other ways:
put cursor in listing, where you want to ungroup
choose from popup menu
>or choose from menu
> >