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