How to use hirarchical category

I’m evaluating Kanboard possibility, and before to start a developpement, I ask the community :

I’m looking for a way to use hierarchicals categories (like in WordPress) :

  • import the category tree into Kanboard from a referentiel
  • link {projects | tasks | subtasks } with one or more category from the category tree

For you, what will be the best way to do it ?