ESS - Org Chart - Hide an employee from ESS Org Chart based on their Process Level and Department

Depending on your requirements it would require either 1) customized security rules for the HS10 token (which is shared by multiple ESS/MSS functions like direct reports) to filter out undesired process levels, or 2) customizing the ESS code to filter out the undesired process levels/departments.

I reviewed the ESS orgchart.htm file in hopes that I would be able to determine if I could customize the code to filter out the undesired process levels/departments but I did not find anything in the code that would allow me to filter out by process levels/departments. Am I missing something (looking at the wrong file)?

That is the correct file; you would have to add code after the AGS calls to HS10 that make Data/DME calls to look up the employee's process level/department and filter out those you don't want.