Making Subitems Appear Under Parent Items in Timeline

I’m having issues with making my subitems appear in dashboards under my parent items.
When i click on the subitems they end up all lumped together in a single category rather than activating under each associated parent item:

How do i resolve this issue because i want my timelines and gantt charts to look like this:

Image found on: The Dashboards – Support

Hi everyone, i found the solution which was not so obvious at first glance.

Basically you have to group subitems under parent:

Hope this works for anyone who has trouble with this!