Call list from another php file

I have the following code now I want Import or call d1 d2 d3 from another file

   private $dlist = [
         "d1; d2","d3",
    ];

For example,

  private $dlist = [
             "('/wp-content/to/d.php');
        ];

or

  private $dlist = [
             "('**otherdomain.com**/wp-content/to/d.php');
        ];