Hierarchies are meant to be created in CRMs. However if you don’t have a CRM, follow these steps to create a hierarchy manually.
In Named Accounts, click the Group by Hierarchy checkbox.
Only non-CRM accounts can be used to manually create a hierarchy. CRM-linked accounts need to have their hierarchies created in the CRM.
Using ctrl+click (Windows) or Cmd+click (Mac), select all of the accounts you want to group together in a hierarchy.
Click the Named Account Actions drop-down and select Link to Named Account.
If you want to unlink accounts, follow the steps above but choose Unlink From Named Account.
Select a Parent Named Account from the drop-down and click Link.
Your named accounts are now part of a hierarchy. Click the arrow to the left to see all of its child accounts.