When you make a team a Split Team, it allows you to split up the team members into different service times. You can schedule or assign people to specific service times so you could have some Ushers at 9am and others at 11am. In order to assign people to those times, you need to create them as Time Preference Options. You can already do that on the Team Settings tab, but we've now added buttons to each Position tab so you do it in the same place you are assigning team members.
If you go to a Position tab on a Split Team, and no Time Options exist yet, you'll now have buttons in two places. There will be an "Add Time Options" button at the top of the position tab, and if you click to assign a person to times, there will always be an "Edit Time Options" button there.