hi,
U wer confusing ofcourse.
may be this is ur sollutn
if u right ckick on any section, u will get the option "insert Section Below"
this will generate a duplicate of that section.
Say, there is one group in ur header. Which means u will have one group header and one group footer.
if u right click on group footer and select "INSERT SECTION BELOW" option.
u will get one more groupfooter of same group.
Please note that: this will not create One more group,instead it is used to create a new section.
U can have multiple "Deatails" section also