To move an item from subcategory to the main category,
More > Income / Expenses Category Setting
For example, you want to move the "Friends" item in the subcategory to the main category.
1. Select the "Friend" item in a subcategory.
2. Tab the "Main Category" button on the top-right corner and confirm.
3. You can now see “Friends” has become in the main categories among your other main category items.