Not sure about standard Pipeline scripts, but in a Declarative Pipeline script, for a given global variable built via:
Jenkins -> Manage Jenkins -> Configure System
The output in the script is:
In Freestyle scripts the WORKSPACE and JOB_BASE_NAME values are expanded at build time. We use these as a nice way to have a few consistent job behaviors across all jobs, but without variable expansion, it seems we have to build and maintain variables in each job script.