Aleksandr

if ($host = "www.sub.domen-1.ru"){ rewrite ^/(.+)\.(ico|png|gif|jpg|jpeg|pdf|css|js)$ /site/sub.domen-1.ru/$1 break;}

RewriteCond %{HTTP_HOST}    ^www\.sub.domen-1\.ru [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)\.(ico|png|gif|jpg|jpeg|pdf|css|js)$ /site/sub.domen-1.ru/$0 [L,NC]

if ($host = "www.sub.domen-1.ru"){ rewrite ^/(.+)\.(ico|png|gif|jpg|jpeg|pdf|css|js)$ /site/sub.domen-1/$1 break;}