Sub menu items at 2nd level or further do not show in service portal header.
Steps to Reproduce
1. Activate the Service Portal plugin on a pre-Madrid instance.
2. Select Service Header Menu "SP Header Menu" form Service Portal > Menus.
3. Click on 'New' from the Menu Items related list:
4. Click on 'New' from the level 2 Menu Items :
Label: Sub menu
5. Click on 'New' from related list Menu Items under level 2:
Label: Order a iPhone 6s
Type: Catalog Item
Catalog Item: iPhone 6s
Observe there is no menu item showing under the level 2 menu.
This problem is fixed in Madrid. There is no workaround. If you are able to upgrade, review the Fixed In or Intended Fix Version fields to determine whether you are able to upgrade to these release/s to receive a permanent fix.
Related Problem: PRB1289758