The functionality is not available in the current version of the RadTabView control. However, we might consider implementing such feature at some point so I have logged it as a feature request in our Ideas & Feedback
portal. You can track its progress on the following page - TabView: Support sliding in the Header
. I have also added some points to your account for the suggestion.
Have a great rest of the week.
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Feedback Portal
and vote to affect the priority of the items