Where is the attachment path of a process attachment based from?

I am writing a scriptlet that returns true or false based on the values of multiple attributes and setting that scriptlet (after configuring to allow process attachments) as a Script Based Condition.

I can see the local file path (like Finished.js) and then the attachment path of /workitem/scripts/common/Finished.js.  Where is this attachment path based from?  I'm assuming it is off of the RTC installation directory, although the beginning slash would indicate that it would be in the root of the install drive?

Susan