How do nested variables within the .env file work in CodeIgniter 4

To add onto this:

I've tried the following

Code:

CI_ENVIRONMENT = development
x = test
somerandomvariablename = foo

control = ${CI_ENVIRONMENT}
google.redirect1 = ${x}GoogleLogin
google.redirect2 = ${somerandomvariablename}GoogleLogin
justatestwithnodotinvarname = ${somerandomvariablename}GoogleLogin

Which produces the following in print_r($_ENV):

Code:

[CI_ENVIRONMENT] => development
[x] => test
[somerandomvariablename] => foo

[control] => development
[google.redirect1] => ${x}GoogleLogin
[google.redirect2] => ${somerandomvariablename}GoogleLogin
[justatestwithnodotinvarname] => ${somerandomvariablename}GoogleLogin