Create subtags (nested tags) to grow a hierarchy of sub-groups.

1. Open a notebook.
2. Tap the button Lasso-Tool on the toolbar, then select Tags.
3. Pick a suitable name for your subtag. Subtag is a type of tags that are subordinate to another tag to divid a group into smaller groups under the same umbrella. 
4. Add a slash and name of a subtag after a tag, i.e. Tag/Subtag. Read these examples: #2022/Jan vs #2022/Mar; #Maths/Calculus vs #Maths/Algebra; #personal/car maintenance vs #work/proposals
5. Grow the hierarchy further with more levels of subtags in similar format, i.e. Tag/Subtag/Subtag/Subtag, etc. Read more examples: #meeting/Team A/agenda vs #meeting/Team B/meeting notes.
6. Type in (or write)  a name in the box to create your subtag. 
7. Tap Done. The tag will appear in the centre of the note.