Editing the design dialogue can be configured apart of the template in two ways:
1. /etc/designs - https://www.youtube.com/watch?v=mlOCwLRcLnI
2. Editable Templates - https://www.youtube.com/watch?v=TiLkvioz0Mk
When design dialogues are declared, the value can be used by all components.
The tutorial videos provide a great understanding and instructions for how you can achieve your question.