Can there be a sub tasks and sub-sub tasks to the Cards in Trello? I have created a board and am adding tasks as cards. The tasks have various Sub-tasks, is there a way to add them as sub-cards?
In the past few weeks Trello announced a new power-up called "Hello Epics" that sounds to do exactly what you are looking for: https://blog.trello.com/trello-card-dependencies-hello-epics-power-up
Disclaimer: I am not in any way affiliated with Trello or Hello Epics, just a very happy user.
We've released a free Power-Up that allows creating hierarchies and tracking progress of epics on Trello boards. You can learn more at https://screenful.com/epics-for-trello