Can't retrieve data from settingspage / group

I have a settingspage 'samenstelling' with a custom-field group 'partij-samenstelling'.
The custom-field group has 3 groups: ps_fractie_group, ps_lijst_group and ps_bestuur_group .

I can't retrieve information from the settingspage / groups. I try different id's but it goes wrong.

$group_values = rwmb_meta('ps_lijst_group', ['object_type' => 'setting'], 'samenstelling');

What can be wrong?