Why are Spring libraries including same parent packages made seperate?

I've just noticed two different libraries sharing paths. Example is as follows. There are two seperate packages - spring-boot-actuator, spring-boot-actuator-autoconfigure.

Packages included in these libraries share the same parent package or package path. I can't imagine the things under the hood. Wouldn't this lead to linking errors?

Package a.b.c is different from a.b.c.d, there is no hierarchical relationship between any two packages in Java, as we may assume.