This stackoverflow answer helped a lot. However, I want to search for all PDFs inside a given bucket.
*.pdf
Enter
Nothing happens. Is there a way to use wildcards or regular expressions to filter bucket search results via the online S3 GUI console?
As stated in a comment, Amazon's UI can only be used to search by prefix as per their own documentation:
http://docs.aws.amazon.com/AmazonS3/latest/UG/searching-for-objects-by-prefix.html
There are other methods of searching but they require a bit of effort. Just to name two options, AWS-CLI application or Boto3 for Python.
I know this post is old but it is high on Google's list for s3 searching and does not have an accepted answer. The other answer by Harish is linking to a dead site.
UPDATE 2020/03/03: AWS link above has been removed. This is a link to a very similar topic that was as close as I could find. https://docs.aws.amazon.com/AmazonS3/latest/dev/ListingKeysHierarchy.html