Embedding the classifieds create-new.php file

Hi

I want to embed the classifieds create-new.php file into a buddy press group tab.

I get the following error.

Fatal error: Using $this when not in object context in /my-server-and-theme-dir/create-new.php on line 21

It seems $this works for pages/posts but not buddy press groups tabs. any ideas?

Cheers,

Johnny