Your comments

in my case, most of all I need sorting " by recently created notes", that is recently assigned tag to new notes should be on top. 



maybe it will be more useful, if Cinta remember it as initial state of tree... and we can return to it any time and many times, not only one time after closing.
thank you Chris too, you clarify my similar suggestion, which I tried to bring to Alex in here.
 
if you don't mind, I simplify this idea as naming sorting by tags, it means, notes will be sorted as we see in Tag sidebar.
I guess , it is matter of sorting...

I agree with ChrisCN that, we should group(sort) by tags if we like, 

and  not agree with dear Alex that, a new concept is needed for grouping.

  • There should be natural way of reading, when we press the parent "Health" tag, it looks like this:

███████ Health (parent tag)█████████████████████ 

...

note5

████████████ diet (descendant tag)█████████████████████

note1

note2

note3

.....

note20

.....

note30

████████████  stomach (descendant tag) ██████████████████

note1

note2

.....

note10

  • but now when I press "Health" it looks like this mixed:

"diet"-Note

"stomach"-Note 

"Health"-Note

"Health"-Note

"stomach"-Note 

"stomach"-Note

"diet"-Note 

....

thank you Alex for adding my request here.

I think, capital letters wil be usefull for tag
examples: toDo toRead toLook&Do
this may be used to assine 2 words tags to Notes