Currently it isn't possible to see which tasks are linked as a subtask within the Kanban view, only within the List-view. Is this concept in the pipeline?
@hasker.brouwer - you could toggle on Advanced mode by hitting Ctrl for Windows or Alt for Mac to see the task paths and breadcrumbs. You can also see in the detail panel if the task has subtasks or not. Hope this helps.

Peggy, May 21, 2020
Please do that. Make the subtasks more connected with parents.
Cynk 7, May 20, 2020
Hi all - Hi all! We have introduced a new feature called Task Bundle, which allows you to group the subtasks under their parent tasks so the task hierarchy will be preserved as it is. Check out this blog post for more information! 😃
Note: This feature is only available for Professional, Premium and Enterprise subscription.

Peggy, Dec 13, 2021
⭐️ We have merged your feedback thread with #4175 to consolidate all similar feedback on one main thread.
Peggy, Oct 20, 2021