Hello Civ
It would be a case of opening the other company in a private window if you want to work on them concurrently.As the post above mentioned if you have more than 2 you would need to use a different browser.
At the moment there is not a plan to change this,we understand you may have instances where you need to look at more than one company at once. If you could leave us feedback in the cog in the top right of the product as this will then be looked at by our product developers and the more requests that we do get for this,if it is possible to implement they will look to create a feature where you could not just duplicate company you are in on the browser but have multiple open.
Emma
