Hi again Adriano and sorry for the delay. We have been testing the code you gave me and doing other actions, but the problem is still there.
After Reading your last answer I would like to explain you the structure of the relationships between our types again.
First at all, Type "Entradas" is the default WordPress "Posts" Entradas is only the translation into spanish
Therefore, we have a Parent called Empresas with two childs Smartphones and Tablets. Each child type Smartphones and Tablets have assigned as child Posts = Entradas.
In the settings of each Type we have setting the relationships (Fig 1 attached) and when we write a post, talking for example about a Smartphone we relate this post with his parent, e.g. HTC ONE M8 (Fig 2 attached)
Am I doing it right?
At last, what we want to get is to show information about parent in this selected posts inserting the "Productos Relacinados" view.
Perhaps I am wrong and there are another easier solution. What I want is "as simple as" show parent information into Posts.