For anyone who comes across this scenario, here is how I got it working:


# get the first folder name into a variable ($site_folder)
map $uri $site_folder {
~^/(?P<folder>[a-zA-Z]+)/.* $folder ;
}

...

server {
...


if (!-f $site_folder) {
rewrite ^/[^/]+/(.*) /$1;
}
}



I am aware of the "if is evil" thing but it states that it is safe outside of "location" block. Supposedly safe in "server" context.

Performance seems good so far.