I use a light hierarchical structure to organize my tasks, typically Area > Project > Tasks. In this kind of setup, I often need to see just the tasks (at level 3) for the highest priority projects (at level 2). Would be great to have the ability to create a smart list that filters in tasks (level 3) using priority or tags set for projects (level 2). This would have other usages, e.g. in my example, I could also use Areas (level 1) to set filter in projects (level 2).

If there's a workaround for this, please share. If not, would be great to see this feature, at least for parent-level properties (I understand supporting grand-parent-level or above would get cumbersome).