A set-up splits file for a run in one of the schoolhouse gamemodes (Story Mode, Classic Mode, etc). If you need to edit it at all, you can open it by right clicking the Splits window and then selecting "Edit Splits...", and from there you can add or remove segments from the real time section and update any info to match your run's settings under the "Additional Info" tab.

Note: When you first open it, the window should look something like this. If it doesn't, please feel free to contact me so I can update and fix it.