Hello,

As far as I know UltraTimeLineView does not have such functionality built in that you could set to achieve cross owner selection of the appointment, but you could handle mouse click event end check if the clicked appointment is selected. If it is then deselect it, if not – select it. I have created a small sample to illustrates this. Run the sample, press “Ctrl” and click to select some appointment.

Let me know if you have any further questions.