I went through this a while back, I never quite got it to work, instead
I cheated and just stored the data I needed in an MV attr which I
trivially can read out and loop through.

(Set local variable to src-attr of where I stored it. For each through
that LV. Then current-node is the value I want to work with).

What I really should do for configuration style stuff like this is
really use a GCV. (A mapping table came up as a suggestion but that is
the next idea).

What format GCV would I use, to get a nodeset of values back, that I
could use to loop through in a for-each loop?

Next idea is could I use a mapping table? I could read back the
XML-Data attribute (or whatever the Mapping table stores the XML in),
B64 decode it into a nodeset. Then look through the nodeset and XPATH
out what I need. That feels sloppy though.

Well I could if I had a key I wanted to read a value from. Oh wait. I
know how!

Define the first column of the table as "counter" and then in my loop
(probably use a While instead of for-each) set lv i=1 before the loop,
read the map table for source column "counter" value of i, get the rest,
do my magic, then at the end of the loop increment i.

Hehe. That would work. Sometimes talking out loud is worth it! But I
still want to know how to do it in a GCV.