The parent/child relationship on the Schedule is perfect if you have breakout style sessions. On the schedule, first the user will see the overall parent name with a + to the left of the name indicating it expands. When users click on the parent name they then see all of the breakout sessions that fall within the parent. See screenshot below-
First, setup each parent entry as you would setup a regular session in a new row on the Schedule template. Within the "Schedule Unique Number" column assign a unique ID to the parent entry. When you create the child entries that should be linked to the parent, place the unique ID for the appropriate parent in column W for each child session on the template.
*Please make sure to list out all parent entries with their schedule unique numbers assigned before listing out the child entries.