Hello Babu Prasad,
I noticed this post had not been responded to after a few weeks. Could you provide a few more details about what you were attempting to accomplish and if you found a way to accomplish your goal? Posting a reply will bring this post back to the top of the unanswered and recent content lists in the community where someone is more likely to reply.
I have the same issue.
If you have a dashboard posted on Tableau Server or Tableau Online with a URL action that opens another Dashboard (or web page) the action opens in a new browser window. Ideally, like navigation on the web, the action just opens the URL within that same window. (Like clicking on one of the "More Like this" links in the right side of this page.)