You can see a breakdown of your spending by category, merchant and country on the Analytics screen under the Spending section. Here you will see the top 3 categories, merchants or countries for which you have spent the most according to the tab you select. You can even select a specific day, week or month bar on the spending graph and all values will be updated to show the breakdown for the selected dates.
You can also check a complete and more detailed breakdown of your spending by just tapping on 'See all' on the Spending section. You will be able to filter for specific accounts or periods and the breakdown will update.
If you'd like to see more details about a specific category, merchant or country just tap on them and a detailed transaction list will be shown for the period selected. You can also add transactions to a specific category by clicking on 'Add transaction' from the category detailed screen and selecting the transaction you'd like to assign to that category.