Of course. I will try and explain it. First let me say I take no responsibility for this one whatsoever!
You will find this feature located on the Output tab of the Batch Convert dialog. There is a little checkbox to the right of the folder entry field, to enable it. And to the right of that is a "Multiple resolution..." button to configure the settings.
In that dialog, you can use the + button to create multiple output resolutions.
The entry field on the left of each line is the directory where that particular resolution will be placed; so you can create 4 different resolutions in 4 different directories if desired.
All of this resizing happens after the main convert is finished. The convert progress dialog may report 1 new file, even if you have 4 additional files (for a total of 5) created in the multiple resolutions dialog.
Some additional notes:
-All the resizing done by the multiple resolutions dialog is proportional; your exact x-y dimensions will be ignored as necessary to preserve aspect ratio.
-Although it looks like you can enter arbitrary dimensions, you cannot. If you enter dimensions larger than the size created by the Actions tab, it will be reduced in execution to that size from the actions tab. So in other words, if on the actions tab your resize is to 800x600, and you enter 2000x2000 on the multiple resolution tab, the multiple-resolution copy will be 800x600, not 2000x2000.
-Output files will have the final dimensions in their name.
-All the files created by the "multiple resolutions" feature also get "thumb" in their name. Do not direct your complaints to me.
That's a brief overview. You'll want to experiment on your own. I'll get around to updating the documentation post when I have a chance.
If you find other quirks, please post here. There may be some idiosyncrasies I'm not aware of.