The search bar will access any data that you give it. Ideally, you'd want to the search bar to be working with the data from the same class. Therefore, to have it search the contents of another table view, you'd want that data readily accessible.
Here's a site that gives a tutorial on how to implement a search bar:
Dimensions: iPhone Development: Adding Search Bar in Table View
Instead of having dataSource be a local variable, you would instead set dataSource to be the data from another view:
self.dataSource = someView.otherData;
Or, you can make a copy of that data, and reference the local copy.
Hope that helps!