Hello, 

This would be a new product idea; in addition with adding a full ribbon menu to the spreadsheet. Our spreadsheet does provide custom filtering as explained in this help topic. 

https://www.infragistics.com/help/wpf/spreadsheet-uiu-custom-filter-dialog

However, our XamDataGrid does have Excel-style filtering. But I understand it doesn't behave like a true spreadsheet.

https://www.infragistics.com/help/wpf/xamdatapresenter-enable-excelstyle-record-filtering

You can suggest new product ideas for future versions (or vote for existing ones) at <https://www.infragistics.com/community/ideas>.
Submitting your idea will allow you to communicate directly with our product management team, track the progress of your idea at any time, see how many votes it got, read comments from other developers in the community, and see if someone from the product team has additional questions for you.
Remember when submitting your idea to explain the context in which a feature would be used and why it is needed as well as anything that would prevent you from accomplishing this today. You can even add screenshots to build a stronger case. Remember that for your suggestion to be successful, you need other members of the community to vote for it.

Let me know if you have any questions.

Michael DiFilippo
Software Developer
Infragistics, Inc.