There's an option to do so within the FAB, which I think is only in the alpha release for now.
Thunder App
An open-source, cross-platform Lemmy client for iOS and Android.
This community is intended to discuss features and feature suggestions for Thunder; as well as friendly, respectful talks about Lemmy in general.
Please use the GitHub repository linked below to submit bug reports, so keeping track of them is easier, and make sure to search first if you already can find an issue for your report.
If there are any developers who would like to contribute, feel free to reach out on GitHub!
General Links
Website: Link
GitHub Repository: Link
Matrix Space: Link
Android Releases
IzzyOnDroid: Link
Google Play: Link
iOS Releases
Apple App Store: Link
TestFlight Beta: Link
Related Communities
Nightly Community: Link
It doesnt seem to work like i would expect it to. When i tap it i would expect to get a list of undread only from say the past 24h, but nope. It does bring unread posts to the top but still has read posts under them. Feeder works the way i think thunder should for unread only view.
Interestingly enough, I prefer the current way of hiding read posts because I like to know which posts are still active periodically.