The transactions component visualizes your company's ingoing and outgoing transactions on multiple accounts.
By hovering the pie chart you can see how much your company pays and receives in total and on your currency accounts.
You can drill down into the numbers to see transactions per account by clicking the "Ingoing transactions" and "Outgoing transaction" number.
More help for Transactions
What do the total numbers mean?
How do I select or deselect accounts?