We are using Odoo 14.0 on Ubuntu 20.04 with nginx as http proxy

According to documentation you can use dbfilter on odoo.conf file to select the database depending on the url.
If you use ^%h$ it will match your domain without subdomain to your database (you have to name your database example.com),
if you use ^%d$ it will match your subdomain to your database (if your subdomain is db1.example.com.mx you have to name your database db1)

This is my question:
Is there a way to match both my domains and my subdomains to my databases?

This way when users enters db1.example.com they will access the db1 database and when enters example.com they will access database example.com

I am basing on this documentation
https://www.odoo.com/documentation/14.0/setup/deploy.html