Is there any indirect tag in VT-SCADA?
I'm just want to show multiple devices in one widget. So, like other scada, using indirect tag put in widget and just need to change that indirect tag to show value of different devices.

Support may have a better solution, but the only way around this I could think of is to put your widget on a parameterized page. Then when you open the page, the tag you specify populates the widget.

https://www.vtscada.com/help/Content/D_Tools/Dev_PageParameters.htm

If you create a custom widget, when adding widgets as parts, you can select if the linked tags are absolute, relative, etc.