Copying or moving a nonencapsulated subpackage might be a bit problematic since used declarations may not be available in the new location for that subclass. When copying or moving an encapsulated package or class at most the import statements inside this package or class, including subpackages and local classes, need to be updated.
If you move the package Rotational inside YourModelica as below, it will continue to work without changes since its import statements still refers to YourModelica.Blocks.Interfaces. Maybe if you instead would like to refer the package YourModelica.Blocks.Interfaces, just update the import statement as we have done below.