How to operate the localVariable defined in the sub interface in the parent interface?

Question

Hi team, 
 There are two interfaces, namely interfaceA and interfaceB, and interfaceB is a sub-interface of interfaceA. 
 In the sub interfaceB, two localVariables are defined, namely b1 and b2. 
 In the parent interfaceA, there is a button. I want to implement a function. When the button in interfaceA is clicked, b1 and b2 in interfaceB can be operated. 
 How to achieve it? 
 Is there a recommended solution? 
 
 Thanks a lot!

Abhay Dalsaniya · Answer

Interface A (parent) 
 >> Interface B (child). 
 #1. To access local variables defined in A into B. Pass those local variables as a rule input to B. 
 #2. To access l ocal variables defined in B back to A. Create rule input in B and save the B's local variables into rule input, so that can be accessed in A. 
 Please note, rule inputs are bi-directional it can be used to pass-on the data from parent to child as well as child to parent.