I have a csp page that is using embedded Runtime Expression (https://docs.intersystems.com/ens201817/csp/docbook/Doc.View.cls?KEY=RCS...) and within that expression I am using a $data() modulo 2 to look for root-level data elements (https://docs.intersystems.com/ens201817/csp/docbook/Doc.View.cls?KEY=RCO...).
E.g: