You do not need to subsequently set the empty condition, i.e., "no dependency data". You will find it indirectly in the 1:n nodes.
Negating conditions in a 1:n search for depending data

Negated 1:n relation
No relation data (x)
Find all items that don’t have a 1:n relation at all.
This immediately also affects the already existing 1:n queries of the corresponding node (entries are removed automatically from the search list).
Without relation data (flag)
Find all items with 1:n relation data where no record in the relation list meets all specified search conditions.
Without relation data can be set directly in the editing area for the selected entry and is marked in the search list as a strikethrough entry. Setting the attribute (flag) refers to the 1:n relation as a whole. Here, other search entries in the linked data class are irrelevant.

An entry without the named relation data (strike trough) and an entry with the relation data.
Note: 1:n search entries can only be combined with OR inside the linked object. In other words, search entries belonging to 1:n-associated objects are always AND-connected to search entries that don’t belong to this object.