I've tried to use regexp in dbfilter to instruct odoo 10 to pickup the hostname from subdirectory structure url and select a db automatically... but it doesn't work..

Subdomain dbfilter(working conf):

dbfilter = ^%d$

Subdirectory dbfilter(which did NOT work)

dbfilter = ^mydomainname/%d$

Other details:

Odoo Version: 10

Odoo Module: Website Builder

Main requirement: Access the webpages directly without going through a login screen

My Questions:

1) Is the "dbfilter" made only for subdomain structure and complete domain name structure ?
Or can it be used similar to php's "htaccess"

2) If dbfilter can be used to setup a subdirectory structure, how can it be done?

Coz, CMSs like Wordpress can do a Subdirectory structure as well as subdomain structure when setup in a SAAS model multisite setup

Please give me some examples