Loop second half of bar

In Djay pro 1 for mac on my mixtrack pro 3, the first top right corner button on the sample pad used to allow me to (once a loop has been set) half the loop. However, it would loop the second half of the bar, rather than the first half. 

For example, I set a 1 bar loop with 4 beats in it. I would press this button and instead of the loop then playing beat 1 and 2, it would cut to beat 3 and 4.

I can’t seem to map this in djay pro 2 for mac - does anyone know where this has gone?