I see, thanks, that's much clearer. You could probably do this already with a tiny bit of scripting and the Execute Command on Completion option. In fact, I do something similar: unrar to a common root, then run a script that decides on final destination based on various things.
In your case, you might run something like this Powershell script:
$unrardir = C:\my_unrar_dir
$nasdir = N:\my_nas_dir
$files = get-childitem $unrardir\* -include "*.avi", "*.mkv"
foreach ($file in $files)
{
if (($file.extension -match ".mkv") -and ($file.length -gt 2GB))
{
## large file, process it here ##
}
else
{
## small file, move it to nas ##
move-item $file $nasdir
}
}