I am exactly at the point where you are. I created a field of type "variable_conditions", and I also set something in the "dependent" field. I the catalog ui policy, I see "catalog_item,variable_set,applies_to", and I even tried to mimic that by giving a field that referes to catalog items, a field that refers to variable sets and a field that has a choice list with 2 options: item and set. But even with that, and then setting "dependent" to "u_cat_item,u_variable_set,u_applies_to" didn't work.

Did you manage to get to work, and if so: do you remember (5 years...) how?