Hello Jose
The special groups are used to group common columns together. When you change the layout of your ALV list you will get a dropdown list with all available "special" groups of columns.
A special group is defined using a 4-digit ID and a description which is shown in the dropdown list when changing the ALV layout.
This 4-digit ID has to be assigned to all rows in the fieldcatalog (= columns) which should be grouped together.
Regards
Uwe
