Hide when no relation selected

Much of your code did not get posted…

How are you retrieving the posts to make the button? That’s where the hiding would be done, not in CCTM….

Anything in your template can be handled however you wish — e.g. wrap the html with an if-statement that tests for a value. That’s simplest solution, but the CCTM does offer some convenience methods for this type of thing. See the output filters, e.g. https://code.google.com/p/wordpress-custom-content-type-manager/wiki/wrapper_OutputFilter