Hello,
I am afraid that the functionality from the screenshot is not available out of the box for the TreeList component. The expand/collapse icon can be placed in the beginning of each row by default.
With that said, if you would like to request such feature I suggest submitting a feature request in our UserVoice portal. Based on the traction the request gathers with the community the developers will consider implementing it in a future release.
Regards,
Viktor Tachev
Progress Telerik