Ref. https://codex.wordpress.org/Plugin_API/Action_Reference/manage_posts_custom_column
Just use the WP built in action called “manage_posts_custom_column” and in callback check for the correct column and add simple_field value with the function simple_fields_value :
add_action( 'manage_posts_custom_column' , 'add_new_column_data_in_posts', 10, 2 );
function add_new_column_data_in_posts( $column, $post_id ) {
switch ( $column ) {
case 'premium' :
echo simple_fields_value("simple_field_slug", $post_id);
break;
}
}