Toolbox | Track Tools () | Annotate and Filter | Annotate from Overlapping Annotations
First, select the track you wish to annotate and click Next. You can choose any kind of variant or annotation track as input, and in the next step you can choose any variant or annotation track.
The result of this tool is a new track with all the annotations from the input track and with additional information from the annotations that overlap from the other track. The requirements for an overlap are simply that parts of the annotations have to overlap, regardless of the strand of the annotations (note that this makes it unsuited for comparing e.g. two gene tracks but great for annotating variants with overlapping genes or regulatory regions).