How to Change Depth for a compand gameOjbect in Unity2D?

I have a gameObject composed by a world space canvas with some images and texts.
But since it is not a sprite, it has no order in layer.
So I cannot change the depth of this gameObject dynamically.
The Only way works is setting transform.z, which is really not a good approach,
What can I do?

PS.
I have tried to add the sprite render component to this gameObject, though it is not a sprite.
But the order in layer just don't work.

 

World Space Canvas has a "Sorting Layer" and "Order In Layer" property.

Then you can control the order of the child objects of the Canvas by their actual order in the hierarchy.

 

It works, thank you !