Use Sharing Sets with Campaigns, Opportunities, and Orders (Beta)
Where: This change applies to Lightning communities and Salesforce Tabs + Visualforce communities accessed through Lightning Experience and Salesforce Classic. Communities are available in Enterprise, Performance, Unlimited, and Developer editions.
How: To enable Sharing Sets for Campaigns, Opportunities, and Orders in your org, contact Salesforce Customer Support. Specify which object, or all three, you want to use with sharing sets.