Mod_Rewrite：将所有req重定向到子目录，以便后续重定向不需要子目录

I'm redirecting my root to a subdirectory on my server:

RewriteEngine On
RewriteRule ^(.*)$ /_from_git/$1 [L]

In that subdirectory (_from_git/) will also be .htaccess files with redirects. I want my like below redirects to be exact matches using the start (^) and end ($) selectors, but I don't want to have to include ^_from_git/ in every rewrite.

So my question is - How can I modify my root redirect above, so my subsequent redirects can be like this:

^old_page\.html$ /new_page.html [R=301,L]

and not like this:

^_from_git/old_page\.html$ /new_page.html [R=301,L]

Thanks!

edit: Here you can see the location of my .htaccess files:

Root .htaccess:

Subdirectory's .htaccess:

If you create a /_from_git/.htaccess file then you can have these rules without the need to prefix each rule pattern with /_from_git/:

RewriteEngine On

RewriteRule ^old_page\.html$ /new_page.html [R=301,L,NC]