I need help with a secondlayer dropdown menu

Question:
I have a Menu like this:

Home
About us
Services (Dropdown)
– Engraving (Dropdown)
— Laser engraving
— Manual engraving

Product:
Wix studio

What are you trying to achieve:
I want to be able to also colapse the second layer fo the menu. In this case the Engraving layer.

What have you already tried:
A lot of things. The only thing that works if I put all the services in the top layer.

Additional information:
No information.

Thank you for your help in advance.

You can provide some pics of your setup?