How to properly configure proxy_pass in conjunction with rewrite?

Question

Nginx

There is an example.com domain. Nginx proxies all requests to it to the backend as follows: pastebin.com/wsQXD4QA
You need to somehow configure the redirect so that requests to *.example.com are redirected to example.com/path/*, and to *.*.example .com to example.com/path/*/path2/* respectively. At the same time, so that the current redirect rule works. Is there any regexp that matches the task?