Connect multiple GMB pages within a campaign
In order to connect multiple GMB pages, go to the campaign's Integrations page on the left side menu, go to Local, and select Google My Business.
If you haven't yet connected a GMB page to the campaign, you'll be presented with the first time setup options. Click "Connect New Account".
If you already have a GMB page connected to the campaign, it'll show you the details of the page that is connected. Click "Switch Account" to proceed.
Either way, you'll then be able to either select the GMB pages you'd like to connect from a list of Google accounts already connected to your AA account or add a new one.
Once you've selected the relevant pages for the campaign, hit the "Save" button.