Adjust Configuration As Per http://rtcamp.com/tutorials/nginx-map-wordpress-multisite-static-files-handling/

conf/nginx/multisite/subdir/basic.conf

@@ -1,13 +1,15 @@
 map $uri $blogname{
-		~^(?<blogpath>/[^/]+/)files/(.*)	$blogpath;
+	~^(?<blogpath>/[^/]+/)files/(.*)	$blogpath;
 }
 
 map $blogname $blogid{
-	default "";
+	default	-999;
 
-	#Add list of blogs with their ids. SEE "FILE-HANDLING" SECTION.
-	#/site1/	2;
-	#/site2/	3;
+	# Must Read - http://rtcamp.com/tutorials/nginx-maps-wordpress-multisite-static-files-handling/
+	# example.com/site1/	2;
+	# example.com/site2/	3;
+	
+	include /var/www/example.com/htdocs/wp-content/plugins/nginx-helper/map.conf;
 }
 
 server {
@@ -19,8 +21,8 @@ server {
 	root /var/www/example.com/htdocs;
 	index index.php;
 
-	location ~ ^(/[^/]+/)?files/(.+) {
-		try_files /wp-content/blogs.dir/$blogid/files/$2 /wp-includes/ms-files.php?file=$2;
+	location ~ ^(/[^/]+/)?files/(?<rt_file>.+) {
+		try_files /wp-content/blogs.dir/$blogid/files/$rt_file /wp-includes/ms-files.php?file=$rt_file;
 		access_log off;	log_not_found off; expires max;
 	}