Here is an example how you can set the folder info to a custom iproperty.
You could make that a external rule that is triggered before save:
Dim oDoc As AssemblyDocument = ThisDoc.Document
Dim oPropSets As PropertySets = oDoc.PropertySets
Try
oPropSets.Item("Inventor User Defined Properties").Item("Folder").Value = System.IO.Path.GetDirectoryName(oDoc.FullFileName)
Catch
oPropSets.Item("Inventor User Defined Properties").Add(System.IO.Path.GetDirectoryName(oDoc.FullFileName), "Folder")
End Try
I'm not sure what you mean by release folders and release numbers.
With both examples you can make something that changes iproperties in an occurrence when saving an assembly.
Here is a list of all iproperties: https://modthemachine.typepad.com/my_weblog/2010/02/accessing-iproperties.html
Let me know if you need more help