Convert Repetitions to Loops

If you have multiple, identical MIDI regions in sequence you can convert them to be a loop with multiple repeats.

If you copy an audio region and repeat it multiple times in a row you can convert them to be a loop. I’m not sure if this is useful or not.

Loop regions in the Logic Pro Tracks area — Apple Support

You can loop regions so that they play repeatedly, and extend them to fill any amount of musical time in the Tracks area. When you play the project, the region repeats the number of times you have extended (looped) it.