Thread the cord through the tube on one side of the fitting, until enough cord is available to make desired loop and then thread the end through the tube on the other side and fix in place with locking blocks.
Creating a running loop or noose
Fix only the end on one side of the fitting with a locking block and leave out the locking block on the return, leaving the loop free to run.
Joining two cords:
Attach one cord to the Connector by threading through the tube on one side and locking in place with block. Attach the second cord by repeating on the opposite side.