Daniel

You need to create nodes in the DOM where the second repeater table is bound
by copying the nodes the first repeater table is bound to.  You'll have to do
this in codebehind probably triggered by a button click or such.  Depending
on how your nodes are named you might be able to clone the nodes from the
first group and add them to the second group, or if you have a blank row in
the second repeating table you could clone those nodes and set their values
based on the corresponding row in the first repeating table.  Otherwise
you'll have to manually create the nodes in the second group for each row and
set the data values.  Look at IXMLDOMNodeList and cloneNode(), appendChild()
or insertBefore().

The following example might give you some ideas (it's not exactly what you
are looking for but should demonstrate several ideas you will need)
http://www.infopathdev.com/examples/#Accessing%20and%20Updating%20Repeating%20Ta
ble%20Row%20Cells,%20v1.1

Michelle