Autolayout with merged objects

Hi designers!
I’m trying to create the rounded corners effect and want to keep layout easy to adjust at the same time. Here is an effect I’m trying to achieve: 

But I’d like to avoid manually adjusting the rectangular size every time I’m changing the text. With autolayout I cannot achieve the rounded connection:
 

Can anyone suggest how to keep connections rounded AND to work with autolayout?

Thank you!