In the Mendix documentation I've found the following article. https://docs.mendix.com/refguide/xpath-query-functions It seems that the article implies that you can use these query functions in a retrieve within the modeler. However it seems this doesn't work as the modeler doesn't recognise the mentioned functions. Does anyone know how to use these query functions correctly?
I might be wrong but I believe these functions are meant to be used from Java actions inside an "Core.retrieveXPathQuery" function call. From the modeler you can use the "Aggregate list" action.