Expand option
 

How can i activate or hide the expand/collapse option ? And where can i translate it?

like in this picture => www.firestormpt.com/images/vb.PNG

It is a template edit - you will need to do this yourself (have a look at the page source). Edit the forumhome_forumbit_level1_nopost template.

don't see nothing to translate expande and collapse or to hide or show this option :(

You need to add the code yourself. As I said before, look at the source of the page and replicate the commands used.