selecting more than one dataSource in pdf properties

Is it possible to use more than one model node as a dataSource for an interactive form?

In my Context tree for one of my views, I have two model nodes each representing a different BAPI. I would like to be able to access variables from both BAPI's in my data view when editing the interactive form. Is this possible? I tried selecting the root "Context" but this doesn't seem to work. Either model node can be selected independantly without a problem. Any ideas?

Thanks for the help!!

Matt