Merchandising campaigns can be added either to just 1 Store or multiple ones at the same time, giving you the freedom to add rules on your entire account or some specific Stores.
From the Merchandising overview, choose Single Store to create campaigns for this store only, or Multiple Stores to add cross-Store campaigns.
For Multi-Store, you can choose the exact scope under Modify Scope:
The scope can also be changed later on the Campaign itself:
