Should you need a custom version of NGINX or any other software on directadmin powered server with custombuild 2.x, here you can see a working solution.
cd /usr/local/directadmin/custombuild echo "nginx:1.9.5:" >> custom_versions.txt wget http://nginx.org/download/nginx-1.9.5.tar.gz ./build nginx
Restart NGINX and check it's version:
[root@server custombuild]# nginx -v nginx version: nginx/1.9.5
The same way you can use custom version for any other software supported by custombuild 2 and directadmin, check /usr/local/directadmin/custombuild/versions.txt and copy needed lines from it to custom_versions.txt the same way as described earlier (with your versions of course).