1. Go to Manage Jenkins > Configure System and check 'Environment variables' under 'Global properties'
2. Add a variable called GLOBAL_VAR with the value $HOME/foo and save
3. Create a new job, check 'Prepare an environment for the run' and put DERIVED_VAR=$GLOBAL_VAR/bar in 'Properties Content'.
4. Check 'Restrict where this project can be run' and make it run on a node OTHER THAN master
5. Add an 'Execute shell' build step and add:
6. Run job