Splitting
A layered analytic can split when it uses data-gathering functions (such as get_query) when there is more than one frame available.
For example, you might have used the get_events layer to load a set of three events - the Morning, Day and Night shifts.
When you then use get_query, your analytic will then split - instead of running once, it will run once for the Morning, Day and Night shifts.
All following layers - regardless of type - will also run per-shift.