Posted by Andrew Carver on Oct 04, 2018; 5:46am
URL: https://discuss.asciidoctor.org/How-to-reference-item-by-number-in-autogenerated-ordered-list-tp6447p6491.html

This is somewhat verbose, but it works:

. {counter2:inum}Here is the first item.
. {counter2:inum}This is the second one.
. [[thisone,{counter:inum}]]This is the referenced item. 
. And a final item.

Which one is xref:thisone[{inum}]?

For some reason, I had to use the xref:[] form of cross-reference to make it work.