Filter by "Request created at"

We're using the Salesforce integration for collecting requests from our customers and we'd like to create a report in Aha! that counts the number of new requests per idea for a given time period (e.g. last 2 weeks).

There's a field called "Request created at" which I can add as a column or add as a data field for pivot tables. I need to be able to add this field as a filter.