Need to know whether we can able to automate the Node red Ui elements using the Selenium webdriver.
Why would you want to do that? You have a whole backend node-red where you can capture & react to events. Why bother building a dashboard then automating button clicks etc via a hack?
Steve's question is good. You may wish to revisit your assumptions.
On the other hand, if you want to use Selenium for testing your UI, it is certainly possible. After all, everything in Node-RED is web based.
Microsoft also have some useful tools to use with Selenium such as UI Flow. I think there are also Selenium alternatives that appear to be more feature rich. I've not used them though.
I'd want to know a bit more about your use case before giving an answer. Please elaborate...
I HAVE automated Node-RED Dashboard pages using Selenium (well, actually WDIO within another instance of Node-RED) as a demo of web browser automation.
It can be done, works well, and is stable.
I'd still recommend using the Node-RED WDIO nodes - faster, more features, frequent updates etc. Plus our company wrote & contributed them (so no bias there!).
As others have alluded - it is probably faster, easier etc. to simply interact / update the Dashboard controls, elements, data, properties directly from Node-RED - assuming you have access to it.