Child items aren't showing on Swimlane or Roadmap (Timeline) cards

Problem

In a Portfolio's Roadmap (Timeline) or Swimlane view, you expect to see child items nested under parent cards, but they're not appearing.

Solution

Show Child Items must be explicitly enabled — it's an opt-in display setting, not automatic. On Swimlane, the related Child Item Levels setting is also grayed out entirely until Show Child Items is turned on.

1. Open Format > Layout.

2. Enable Show Child Items.

3. On Swimlane, also set Child Item Levels to the number of child levels you want visible on parent cards.

4. To view or collapse the child list on a Swimlane card, use the arrow next to "Levels" at the top of the Child Items list.