Thank you so much, Florian!
This data model has been set by a third party, who wants me to migrate it to SAP HANA.
The idea is to get the name and description of the group, and display it on different languages, deppending on the parameter "lang".
So it's mandatory the use of projections if you want to get an association, i guess. Because i've been able to access data from a single table without the $project() method. I'm i right?
thank you very much for your help.
Regards,
Luis