I've got a Page structure that appears such as this:

Home
  Page1
    Page1a
    Page1b
      Page1b-a
  Page2
  Page3
    Page3a

Can there be any method of getting just the second level pages (Page1 , Page2 and Page3)??

Thanks ahead of time!

Is Home a real Page? If that's the case you query where post_parent = id of Home. Are you currently writing a question directly from the database or using wordpress_list_pages?

wordpress_list_pages includes a child_of parameter:

wp_list_pages('child_of=#');

EDIT: May use get_pages to drag back a range of pages, virtually same parameters as wordpress_list_pages:

http://codex.wordpress.org/Function_Reference/get_pages