Routine has been designed as a knowledge graph, with objects (tasks, events, contacts, pages etc.) representing nodes connected to one another.
In this giant hierarchy, some objects are upper-level, also known as root objects, while other live in the context of another object, referred to as their parent.
In other words, a checkbox in notes of an event represents a task whose parent is the event itself. The event object is itself implicitly linked to the objects representing the other participants in the event. And so on and so forth.
Organizing information in Routine implies re-arranging the graph, in particular moving an object from one parent to another, which is a very common operation.
Assuming you have a task that you would like to move somewhere else in your organization, open the task and use the ... submenu to access the Move action or use the ⌘/^ ⇧ M keyboard shortcut.
Contact) or through the app.