No one seems to ask this simple question, so I will.
My PowerShell script file is located: C:/this-folder/that-folder/another-folder/powershell-file.ps1
C:/this-folder/that-folder/another-folder/powershell-file.ps1
I'm assuming you want to know what folder your script is running in when it's being run.
This should do it:
Split-Path $MyInvocation.MyCommand.Path