Get File Name and Extension from Path

# Return just the file name
[System.IO.Path]::GetFileName($FilePath)

# Returns file name without the extension
[System.IO.Path]::GetFileNameWithoutExtension($FilePath)

# Returns the file extension only
[System.IO.Path]::GetExtension($FilePath)

PS C:\> $FilePath = "C:\Scripts\ScriptSearcher.ps1"
>> [System.IO.Path]::GetFileName($FilePath)
>> [System.IO.Path]::GetFileNameWithoutExtension($FilePath)
>> [System.IO.Path]::GetExtension($FilePath)

ScriptSearcher.ps1
ScriptSearcher
.ps1