Hi Grzegorz,
Thanks for the update.
As we informed earlier, it is not possible to combine funnel and bubble series in a single chart. We have achieved your requirement using ellipse annotation in chart, to depict the bubbles in the funnel series. Please find the sample attachment from the below location.
Funnel_and_Bubble
Please refer the below documentation link for more information about annotations.
http://help.syncfusion.com/wpf/sfchart/annotations
Please let us know, if this satisfies your requirement.
Regards,
Samuel