In your overview of received attachments, you can easily filter for file types using the ‘Filter’ option. You can also sort your attachments based on time and separate them per time unit (separated per week, month or year).
Using the search functionality, you can also find attachments by entering the file name. Do note that you have to set the filter to only include attachments, otherwise you will see all messages, contacts, co-workers and groups with the same text included.