No simple solution to offer.
However, every row from the dataprovider has a unique rowindex number. So if you build a variable that validates the list of rowindex numbers into 3 groups you can then display the 3 lists side by side (use floor(),mod() and rowindex() functions)
Alternative , define dimension X like:
=Floor(mod(<Rowindex()>/3)) and try to fit this into a dummy crosstab
[no idea if this works, no longer working in a BO shop]
Ties Blom