将主域重定向到3级子文件夹而不更改URL

Let's say my domain is mydomain.com My structure is root>subfolder1>subfolder2>subfolder3>index.php How can I redirect domain so that mydomain.com points to subfolder1>subfolder2>subfolder3>index.php without changing url? I have a htaccess in subfolder3 which takes care of parsing url so it has to be unchanged.

.htaccess code in subfolder3:

RewriteEngine on

RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

RewriteRule ^(.*)$ index.php?path=$1 [L,QSA]

Thanks.

Create a .htaccess under website root with this rule:

RewriteEngine On

RewriteRule ^(.*)$ subfolder1/subfolder2/subfolder3/$1 [L]