Can I navigate to the Playback tab from the my plugin tab in Smart client?

Yes.

Please explore this sample, the Workspace tab..

https://doc.developer.milestonesys.com/html/index.html?base=samples/smartclientview_windowtool_sample.html&tree=tree_1.html

https://developer.milestonesys.com/s/article/Exploring-the-MIP-SDK-Tool-View-and-Window-Tool

I mean can i go to Xprotect Playback tab by click on my Play button?

Yes, hopefully the code in the sample will show you how and you can re-use the code in your solution.

I see. Thank you.