On the Fi Home screen, you will see a search bar. You can use it to search for your transactions by typing terms like - Amazon spends, Zomato spends, Transactions over 1000, etc.
You can even search for a particular person by typing their name. For example, if your friend's name is "Arun Kumar", you can type his name and all the money sent to him or received from him will be shown here.
You can use this only to search for transactions made using the Fi app or a UPI payments app like GPay or PhonePe. Or if you have linked your other bank accounts using the Connected Accounts feature, then your linked bank account transactions will also be searchable.