Hi Gert,
Thanks for contacting Syncfusion Support.
We have checked the reported requirement "Filter and search feature for SfPicker" from our side and in our current implementation we do not have support for this, So, we have logged feature report for same. If needed we can workaround to achieve your requirement by placing the Entry in the top of SfPicker and based on entry text we can implement our logic and filter by changing the ItemsSource dynamically in SfPicker.
This feature will be available any of our upcoming volume releases.
Please let us know if you have any other query.
Regards,
Rathanakumar S.