Firebase hosting with multiple directories at multiple domains

Question

I have the following setup and wanted to know how to best configure Firebase hosting

I have a repo with the /build directory with three subdirectories:

Answer 1

You can host multiple site on Firebase now.
https://firebase.google.com/docs/hosting/multisites?authuser=0

Answer 2

This would require setting up six projects (one for each prod/dev environment) and three firebase.json files. You can associate multiple domains with a single site, but at present you cannot have multiple sites in the same project. This is something that we're looking into supporting in the future, but there's nothing to announce at this time.