I want to show relational posts in the admin columns.
I've created a relation between 'Aandoeningen' and 'Behandelingen'.
I've installed and activated MB Admin Columns and added 'admin_column' => true, (or 'after title') to the relation:
But the relational posts are not shown in the admin columns:
I guess I'm missing something, but what?
Please, help me out.