Spy tool unable to recognize the popup window (wpf application)

Hi,

We're trying to identify a popup object within the wpf desktop application.

This is a filter applied to syncfusion grid header column to filter the data. 

When spied entire popup is identified as one object with the full class name System.Windows.Controls.Primitives.PopupRoot

Note :

We tried composite controls it didn't work with this.. we even tried all syncfusion control supported still facing the issue with object identification 

Thanks in advance