The detail section is nothing more than a section that repeats for every
record. All you need is to add a group header or footer based on a field
or expression that is different for every record in the RecordSource. It
will then repeat once per record just like the detail section.
I would add though that in many years of working with Access I have never
encountered a need to do this so I am curious about what you're trying to
accomplish. A 1/4" inch high detail section followed by another 1/4" high
detail section will look and act the same as a single 1/2" high detail
section. The only immediate difference I can think of is that you could
independently cancel one of the sections without canceling the other.