Do you plan to implement nested tags?
If by nested tags you mean the ability to search for more than one tag, then this is already implemented. Try clicking a tag on the tagbar (dark sidebar to the left) and while holding shift clicking another one.
Customer support service by UserEcho
Ideas
If by nested tags you mean the ability to search for more than one tag, then this is already implemented. Try clicking a tag on the tagbar (dark sidebar to the left) and while holding shift clicking another one.