Center admins can only see transactions in the security category applied to their admin group.  In order for admins to see transactions across centers, you'll want to add an override to the security category's "Cross Center Transaction Management" permission.  For example, if you have a transaction that is listed under the General security category and you want admins across other centers to view this transaction, you would make the following changes:
  1.  Setup>Security Categories
  2.  Click the General security category name
  3.  Click Category Permissions
  4.  Select Cross Center Transaction Management from the drop down list and click Choose
  5.  Click Add an override
  6.  Select Center Administrator Groups for the Group Type and the appropriate Group Name
  7. Select the View Cross Center Transactions radio button and click Save