The location of these parts is dependent on whether you are running the chains over the motor sprocket or under (you will be asked about this in the initial calibration setup)
over the sprocket (this entire subject post is a very informative for different options on chain tensioning)
Thanks to @Dustman for this excellent picture
but basically they are placed on the slack side of the sprocket to keep the chain from crossing itself and to keep more chain links in contact with the motor sprocket to reduce chain skip.
hope this helps