So, for the time being, this is not possible. Once the framework provides an implementation and we also provide our own on top of it, we will definitely document the feature.
Regards,
Marin Bratanov
Progress Telerik UI for Blazor
We haven't gotten to tackling this yet. It is coming up pretty soon on our roadmap, and it is planned to be handled before R1 2020. I can suggest you monitor our release notes, we also have an RSS feed for them.