subdomain rewrite rule lithium framework

Question

I plan to have this as a URL:

https://SubDomain.domain.com/<locale>/Controller/action/param1/param2/?query=param3

in Lithium Framework (li3.me) What is the purpose of the htaccess files in Lithium?

It should redirect me through .htaccess as:

https://domain.com/<locale>/Conttroller/action/param1/param2/?query=param3&subdomain=SubDomain

In Lithium framework there are 3 .htaccess files:

1. /.htaccess
<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteRule    ^$ app/webroot/    [L]
  RewriteRule    (.*) app/webroot/$1 [L]
</IfModule>

2. /app/.htaccess
<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteRule ^$   webroot/   [L]
  RewriteRule (.*) webroot/$1 [L]
</IfModule>

3. /app/webroot/.htaccess
<IfModule mod_rewrite.c>
  RewriteEngine On
  # Uncomment the line below, to enable HTTP authentication running PHP as a CGI.
  RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !favicon.ico$
  RewriteRule ^ index.php [QSA,L]
</IfModule>

I tried to edit the root /.htaccess file to get the subdomain name as a parameter without any success.

Pass subdomain as parameter

Dynamic subdomain rewrite htaccess

.htaccess Wildcard Subdomains

RewriteCond %{QUERY_STRING} ^$
RewriteCond %{HTTP_HOST} !mydomain\.com$ [NC]
RewriteRule ^(.*)$ app/webroot/$1?subdomain=%1 [L]

Do I have to rewrite rules in all 3 .htaccess files? If so, what are the changes needed?

Thanks!