Get sidebar on other php pages

Hi there,
I am really new to php and I’m having some problems.

The problem is that I want to add the sidebar from my blog section to another php file, which is in an upper directory of my website.

How can I call the sidebar.php effectively to display the same sidebar?

I tried <?php get_sidebar(); ?> and <?php get_PATH TO sidebar.php but it doesn’t work apparently!

Any help would be appreciated! Thanks! 🙂