PHP require file path in Wordpress?

Im getting the following error:

Warning: require_once(public_html/http://ift.tt/1jDd4J8): failed to open stream: No such file or directory in /home/bodybui7/public_html/http://ift.tt/1XFqYx7 on line 11

How do I get the right file path from one plugin folder to the next?

via Chebli Mohamed