Returning a property of the old parent value in an expression

Summary/Content:

In order to support some validation requirements we have, we would like to be able to return in a validation expression, a property X of the old parent of a node and check if it equals property X against the 'to be' parent. Is it possible to return the old parent/a property of the old parent?

Version (include the version you are using, if applicable):

25.08.64