$meta_boxes[] = array(
    'id'       => 'select_post',
    'title'    => 'Post Selector',
    'pages'    => array( 'post', 'page' ),
    'context'  => 'normal',
    'priority' => 'high',

    'fields' => array(
        array(
            'name'  => 'Post',
            'desc'  => 'My Post Dropdown',
            'id'    => 'my_post_dropdown',
            'type'  => 'post',
            'query_args' => array(
            	'tax_query' => array(
            		array(
            			'taxonomy' => 'category',
            			'field'	=> 'slug',
            			'terms' => 'technology'
            		)
            	)
            )
        ),
    )
);