Hi,
You can easily test it, with severals JOBS "test" in a WORKFLOW.
If you click "Restart" on the job2, the job2 will be executed, and if success, the job3 will be executed too. The job1 will not be executed because he is before the job2 in your workflow
If you want to execute only the job2, search it in the explorer, right click, then "Execute".
Séb