Integrating your Google My Business with a campaign is easy. Just go to the campaign you want to integrate by selecting it in the campaign dropdown on the left under the navigation or in the list of campaigns in the main page, then settings / integrations.
You will see the list of the different integrations possible.
Click on "Authorize" in the Google Analytics box. The system will then ask you to identify yourself or choose a Google Account linked to the Google Analytics account you want to access.
Once done, you can choose among the different profiles of the Google Analytics account that you connected. Then you will need to choose a location.
Click Save Changes.
You can change the integration by clicking Manage, or totally disconnect the account by clicking Disconnect.