I have a Hampton Bay Fan with remote that has a Fan Off button and Lo/Med/Hi buttons but no reverse button. There is no visible switch or chains on the fan to reverse the fan. Is there a sequence of pushing the buttons that will reverse the fan or another method to do so?

If there is no reverse button on the remote, and the remote is original to the fan, then the reverse button is somewhere on the fan body. Sometimes it is hidden.

It is also possible that the original remote had a reverse button and this is a replacement.

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More