When using Grist hosting, teams are added as subdomains, which works very nicely, for example
myteam.getgrist.com
When self hosting, teams are added as a folder after the domain, for example mydomain.com/o/myteam.
Is there any way this can be setup as myteam.mydomain.com instead? Are there any environment variables which do this?
If you set GRIST_ORG_IN_PATH to false, Grist will attempt to extract a team from the domain name. You’d also want to carefully set the domain for cookies, using GRIST_SESSION_DOMAIN to .mydomain.com in your example if you want cookies shared across the teams. It would also be important NOT to set GRIST_SINGLE_ORG if you have been using that up until now.
You’ll also need to tweak your reverse proxy to deliver traffic to Grist for all the subdomains. I think Grist may also expect a docs subdomain to be available for personal sites (you can turn these off with GRIST_ANON_PLAYGROUND=false).
Just a heads-up: this configuration isn’t something we can offer a lot of support for, since by its nature it can be easily broken by configuration details outside of Grist.