Dependencies (Page/Select) with "AND" selector

[August]

Hello, I've been trying to create a selection for a dynamic selection field for days now.
This ist the working statement in the Admin-Backend of the field (Page/select - not Multiselect or AM) and I also tried/played around with a hook in ready.php,but the result remains the same:

parent=page.helper, refSeries=page.selectManufacturer, pages_subcat=page.selectSubcat

However, the current status requires pressing Save to reload the changes.
It would be good if this could be done like the other dependency fields.
I've also tried some sort of pre-select field to get the desired results from its result.
Unfortunately, does anyone have an idea or a tip on how I can solve this, maybe with a Hook in "selectablePages", add(pages->find...)?

I appreciate any support that leads me in the right direction, thank you in advance