How to switch companies (domains) in jira when being part of multiple projects

[crtl]

Im working in Projects in multiple companies which each have an own jira board including domain.
Im a member in both companies/domains with the same account.
How can I switch and see all the companies im part of in jira without manually typing in the other domain in the browser?

[Mark Segall]

Hi @crtl 

I've found the easiest way is clicking the box at the top left of the screen and clicking "Atlassian Start"

From there you'll see the various instances you have access to.  

Personally, to keep my instances straight, I create a new browser profile for each instance and apply a different browser theme to each profile.