If you have worked with earlier versions of Dynamics CRM, you might have faced common requests from your clients to customize social panes to sort activity based on the created-on date or any other date apart from modified on, which was the only option available. But before Dynamics 365 there was no way to do this, as we can’t do any customization in social pane and there was no configuration option as well.
Not we only have this sorting option available but we can also configure sorting field based on our requirement. We can change this property from form editor by setting social pane properties. We can double click on social pane and configure Data fields under Activity Wall like following,