Show children and grandchildren with titles and thumbnails

Hello everyone!, first post here!

I’m having a hard time to figure this out, I want to make a page template to do the following:

list all the children and granchildren of the current page, but in a hierarchical way

Children should work as the title for the grandchildren, goes something like this:

Parent Page (the title of the parent page, should not be seen)
– Child A (this would work as a title with no link)
— Grand Child A (this would have “the_title()“, “the_permalink()” and “the_post_thumbnail()” )

— Grand Child B (this would have “the_title()“, “the_permalink()” and “the_post_thumbnail()” )

– Child B (this would work as a title with no link)
— Grand Child 1 (this would have “the_title()“, “the_permalink()” and “the_post_thumbnail()” )
— Grand Child 2 (this would have “the_title()“, “the_permalink()” and “the_post_thumbnail()” )