xpath reference selector

Hi,   As a new user of Mendix, I'm still struggling with defining xpath constraints and hope someone can help me what I'm doing wrong. I have a reference selector that has to show only the courses (Vakken) it is allowed to show for that specific period (Periode) part of the screenshot (VakPeriode is an extra entity cause of more-more relation between Periode (period) and Vakken (courses))     The picture above listens to a dataview where you have to select the Periode (period) first. The xpath (in the tab selectable objects) I thought I could use was: [Masterdata.VakPeriode_Vak/Masterdata.VakPeriode/Masterdata.VakPeriode_Periode/Masterdata.Periode = '[%CurrentObject%]'] But this is returning an error once I load the page in the picture above   Hope someone can help me.
1 answers

You can create an association between Vak and Periode, doubleclick the association line and select it to be an n-m association.

One mind-change you have to make when starting with Mendix is that every association, on database-level, is in fact a separate table by itself. Seeing is believing, so run your app locally, then in Studio Pro click Console => ‘Start built-in database viewer’ and look for tables that have name that corresponds to one of your associations.