No we currently only have one parallel looping set of nodes. However extending them (and especially having a group version) is on our feature list. I keep you posted when there are any news.
As a workaround. Instead of looping over the table, loop over a list of the grouping columns values (unique) with the parallel loop start node. Than use inside a table row to variable loop start and filer the whole data table using the generated flow variable. This will give you the group part of your table.
I hope this helps,
Best, Iris