さすがにそんなシンタックスはないが同じような動作はできる

$continuation = @{
  A = { select Name,Age | Write-Host -f Cyan }.GetSteppablePipeline()
  B = { select Name,Gender | Write-Host -f Magenta }.GetSteppablePipeline()
  C = { select Name | Write-Host -f Yellow }.GetSteppablePipeline()
}
$continuation.Values.ForEach("Begin", $true)

@"
Name,Age,Gender
A,12,Male
C,93,Female
B,32,Male
A,52,Female
C,73,Female
"@ | ConvertFrom-Csv | foreach { $continuation[$_.Name].Process($_) }

$continuation.Values.ForEach("End")