How to write a rule which can iterate over multiple level of fact field List ?

Issue

• Consider this typical example of a fact whose specific field is a java.util.List of another fact type, and that internally refers to a java.util.List of another fact type. Here is an example of how the internal fact hierarchy could look like.

Fact: A

package com.sample.test;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.kie.api.definition.type.Label;

public class A
  implements Serializable
{
  static final long serialVersionUID = 1L;

  @Label("B nodes")
  private List<com.sample.test.B> bNodes = new ArrayList();

...
}

Fact: B

public class B implements java.io.Serializable
{

   static final long serialVersionUID = 1L;
...
   @org.kie.api.definition.type.Label(value = "parameters")
   private java.util.List<com.sample.test.C> parameters;
...

}

Fact: C

public class C implements java.io.Serializable
{

   static final long serialVersionUID = 1L;

   @org.kie.api.definition.type.Label("name")
   private java.lang.String name;

   @org.kie.api.definition.type.Label(value = "value")
   private java.lang.String value;

...
}

The requirement is to create a rule that iterate over the List of bNodes from the above example and, for each B type iterate over the parameters type, to update a field from fact C , using a function in DRL. How to achieve this requirement?