Did you know that you can use multiple wildcards in paths? This will give you a lot of control. Check this out:
This line will find all DLL-files in all sub-folders up to two levels below your Windows folder:
Resolve-Path $env:windir\*\*\*.dll -ea 0
And this line will lists the Desktop folder content for all user accounts on your computer-provided that you have sufficient privileges:
dir c:\users\*\desktop\*