help you fix your problem Are you using iframe to embed the exported kibana dashboard on to meteor? If so, then it will hide the left side dashboard of kibana. If you observe the query string of the iframe, you will see ?embed=true. Remove the embed=true part to enable kibana's sidebar on the embedded page.
it fixes the issue You cannot know which other tabs are open on the same page/site, but you can communicate between them. You could periodically (through a timer) check for a given cookie, or you could listen for changes in sessionStorage (setting a value from the tab where login happened). You could also check with the server, using polling, long polling, server side events, or a websocket.