There are multiple options.
With the Python API you can use the copy_tree() method.
import ncs.maapi as maapi
import ncs.maagic as maagic
m = maapi.Maapi()
m.start_user_session('admin','system')
t = m.start_write_trans()
root = maagic.get_root(t)
for s in root.src__src:
print 'copy {}'.format(s.my_key)
d = root.dst__dst.create(s.my_key)
m.copy_tree(t.th, s._path, d._path)
In this case, src and dst are two lists with similar data structures, and a key leaf called my-key.
The code copies all list entries in src to dst.