When you extract parameters into the Master parameter set then you can drill down into the tree and see where the parameter came from. You do this by double clicking on the parameter name in the Parameter Sets subject area of the tree. This will show you the servers which the job came from. Double click on that and the project names will appear. Last double click on the project name and the job names of where this parameter is being used. This is only as accurate as the last extract. So if you have added this parameter outside of Parameter Navigator then you need to extract job parameters to update the repository on Parameter Navigator.
When you extract a parameter it will not overwrite the Master. This is very important. You want to deliberately change your Masters.
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