Dynamically insert CMB2 function to custom post type loop

I need to display post from custom post type name “film”, from a specific taxonomy “Horror.”
Everything work fine when I type the taxonomy directly like this:

        <?php  $blog = array(
        'post_type'         => 'film',
        'catfilm' => 'Horror',						
        'post_status'       => 'publish',
        'posts_per_page'    =>4,
        'ignore_sticky_posts' => 1,
         );
     	?>

I need to insert dynamically the taxonomy with CMB2, so I change the code like this, but no luck. The post failed to appear:
My CMB2 function:

	$cmb_tvseries->add_field( array(
		'name'        => esc_html__( 'Sub Title', 'cmb2' ),
		'description' => esc_html__( 'Subtitle for your main Title', 'cmb2' ),
		'id'          => 'mytheme_catfilm',
		'type'        => 'text',
	) );

My loop change to:

      <?php $blog = array(
    	'post_type'         => 'film',
    	'catfilm' => '<?php echo ( get_post_meta( get_the_ID(), "mytheme_catfilm", true ) ); ?>',						
    	'post_status'       => 'publish',
    	'posts_per_page'    =>4,
    	'ignore_sticky_posts' => 1,
    	);
    	?>

I am newbie on php. Please help.