Showing the “better together” story of SharePoint and Yammer is the ability to start a Yammer conversation in an Office 365 document.
The “how to use this feature” bit is found here: https://support.office.com/en-us/article/Start-a-Yammer-conversation-in-an-Office-365-document-6fa52987-4264-4246-a7b1-dcaa0ab5500f
Getting the document there in the first place is a little trickier – especially if you are a member of multiple Yammer networks.
In any SharePoint library press the three little dots next to a document, and select post:
However be wary – by default this will post to the last Yammer network you were using.
No document, I do not want to post this Paradyne internal document to the Microsoft Band User network.
The problem here is that you can’t switch networks from within this popup. I wouldn’t call it a design flaw. That ability would be nice but the reality is that most users are probably members of only their corporate network.
If that isn’t you and you are a member of multiple networks – make sure you switch to the desired Yammer network first, THEN post the document.
By default it will post to the All Company feed:
However this you can change by pressing the X and typing in the group you would like to post to instead: