If you want a deeper way to organise your notes, Bear allows you to structure your tags in simple hierarchies. Let's say you have a recipes tag which contains all your favorite food preparations, but you want to quickly find all the vegetarian ones. In this scenario all you have to do is to insert this tag in all your vegetarian recipes:
/ symbol tells Bear to manage the tag as a hierarchy where
recipes is the father tag and
vegetarian is its child.
All the parent tags will be shown in the Sidebar with a little disclosure button on the side. Selecting the disclosure will show the child tags related to the current parent.
For a more sophisticated tagging use as many tag levels you want. For example you can use dates as tags to have your notes sorted like in a journal. In the screenshot below we used tags like this: