I’ve researched this and, having been led here and after trying for several times doing it on my own and getting inconsistent results, it seems that it is not possible to link private entries together.
I was intending to create private anchors and link specific private entries to each one of them, in order to call hdk::get_links on a specific anchor and get my desired entries. However, the results are inconsistent and sometimes wrong. My question is: is there a way to achieve this, instead of having to go through all the entries from a certain type and filter each one?