From the next update Midrub will allow you to update your Google Business account. Works in the same way like all other social networks. You just need an approved api access. After approvation you will be able to publish posts in your locations. I will add insights even for Google My Business.
When you connect Google My Business, Midrub takes all your locations and connects them as accounts. Next you can publish in these accounts.
Midrub allows to publish on Google My Business your text messages, title is supported, urls and images.
The published posts on Google My Business will be visible in Google.