Odoo13 configuration question

I have the following config:

dbfilter = ^%h$

This means that if I go to test1.domain1.com it will open the database test1.domain1.com and if I go to test2.domain2.com it will open test2.domain2.com database. so it matches domain name specifically. Which is what I wanted and works 100%.

However, I would like to also specify the following:

If I go to test3.domain2.com it must open the database test1.domain1.com just as test1.domain1.com in my example above.

I assumed I can do this by doing the following:

dbfilter = ^%h$
specific_url_db=test3.domain2.com:test1.domain1.com

It isn't working as I was hoping. But as you can see I want the domain-specific filter to work at the same time with specific domain name overrides.

Is this possible and how would one go about doing this?

Thanks in advance..