The capability exists to work with several Instruments on one Chart simultaneously.
To do this you need to add one more instrument to your Tester, by clicking the Instruments... button in the top left corner and clicking Add new: Instrument to handle quotes from both of them.

To activate one of the existing instrument click on them or right-click and press Activate. Also you may Change symbol name, Remove and edit instrument Settings.

Comments
multi-currencies chart
How can I use a multi-currencies chart?
Thanks!