Either click the Insert Section button in the toolbar (to affect all tracks, regardless of selection), or choose Edit > Cut/Insert Time > Insert Section at Playhead.
All selected regions are cut at the left locator, and a passage of one cycle length is inserted. Regions currently in the Clipboard are then pasted at the playhead position.
Tip: This workflow is perfect for when you want to insert a part (a chorus, for example) at another point in your arrangement. To guarantee all tracks are shifted, including tempo, time signature changes, and markers, make sure everything is selected (using Command-A or Shift-I) before cutting and inserting.
In Logic Pro, set the locators to span the section you want to repeat (bars 5 through 8, for example).
Select the regions that you want to repeat. If no selection is made (or if you use the Repeat Section button in the toolbar), all regions that fall between the locators are affected.
Logic Pro Effects: PDF