Easily? You can’t. dBlue created a Tool to make it as easy as any method I can think you ever could with a tracker without managing to play to a metronome to start.
So once you manage to get your pattern sounding OK looping, even at an arbitrary number of lines (starting with high BPM/LPB could be useful) you can then resize to the amount of lines you want. Can see it only really working with short recordings of a single pattern length though, unless I’m missing something.