The set is usually for 4 or 5 couples and Starts with 1st couple of the Full set. Once they have Progressed to a specified Position Down The set, the Couple now in 1st place Start the Repeat as 1st couple of the new Active set from the first bar of the Repeat While the 1st couple of the Full set continue with the remainder of their Repeat. Of course, the deviser must ensure that the instructions for one Repeat make this possible without conflict.
Farewell to Balfour Road is a typical example in a 5 couple set; after 16 bars, 2nd couple (in 1st place) Start the new Repeat with 3rd couple (now in 2nd place) While 1st couple continue for another 16 bars with 4th and 5th couples.
London's Burning is a more complex example in a 4 couple set. After 16 bars, 2nd couple (in 1st place) Start the new Repeat; 1st couple are in 3rd place from which they share in Reels of three on the sides with 2nd couple and 3rd couple (now in 2nd place); for the final 8 bars of their Repeat, 1st couple Progress to 4th place.