In Global Navigation, click the Campaigns link.

You can view sub-accounts associated with campaigns on the Campaigns Overview table.

In the All Campaigns tab, click the Fields drop-down menu [1]. Click the Sub-account toggle [2] to display the sub-account field in the table.

You can also view which sub-account is associated to individual campaigns by viewing the Campaign Details.

In the All Campaigns tab, to access the sub-accounts linked to a specific campaign, select the campaign you wish to view.