show availability from multi accounts

Consider this example ... I am a Project A person who is working 25% on Company 1, 75% on other clients. I need to make my Company 1 meetings visible in my Project A calendar so people don't double book me when it looks like I'm free.

I have 2 different O365 accounts ( mailto:me@Projec mailto:A@A.ca and mailto:me@Copany1.ca ) 

How do we manage this scenario? Is there a way to show overlap view of all my calendar accounts to other people in Outlook?