Now, what does the Hierarchical mean?
The Hierarchical custom fields feature allows you to build tree-like menus to be shown to the customer before the start of a Live chat session.
You can set up everything as usual, the ident, Label and other properties. In type choose Hierarchical.
To enter the content, lookup your new field in the list and click „Edit items“ and then „Create value for the custom field.
Now you start to enter the first level of the menu. Enter the label and move on to another, the parent field remains empty for now.
When done, you can start adding the next level directly by clicking on the „Add item“ by the first-level item.
This time, the parent id is going to be the related general category. This new item is going to be nested under it.
This is what is it looks like in the end. You can add even more levels in vertical if you like to.