Your company managed project used 4 issue types: Epic, Task, Bug, Sub-task. You need to show all sub-tasks visually on the kanban board beneath their parent. INCORRECT! Quick filters will filter view of cards on the board but not group sub tasks visually. INCORRECT! Basing swimlanes on epics will show issues under the epic and cant be collapsed separately from the epic. CORRECT! Basing swimlanes on Stories will show sub-tasks grouped beneath their respective parent Bug or Task and can be collapsed or expanded. INCORRECT! Basing card colours on issue type will disginguish the various issue types, but not group sub-tasks beneath the parent. INCORRECT! Regardless if you have “open issues in sidebar“ or “open issues in dialog“ selected, you will already see the sub-tasks in that window and not on the board.