Breitling don't make their manuals available on-line but you may be still able to order one through an AD.
The Chase-Durer Squadron Commander uses the ETA Cal. 251.262 movement which is similar to the one used in your M1. Instructions for setting sub-dials are the same for both.
To adjust the 1/10th sec sub-dial, pull the crown fully out and press the lower pusher to move the hand around to zero.
To adjust the chrono seconds hand, pull the crown fully out and press the upper pusher to move the hand around to zero.
To adjust the chrono minutes hand, set the crown half way out and press the lower pusher to move the hand around to zero.
To adjust the 12 hour sub-dial, set the crown half way out and press the upper pusher to move the hand around to zero.
Download the manual here http://www.chase-durer.com/pdfs/manual_squdroncommand.pdf