I got the answer for this question after doing some research. I thought it would be helpful for you people too.
The guide builder is designed in such a way that it will not get the subform logic to be implemented in form guides. If we need the same functionality, we need to replicate the same code using panels as a replacement for subforms in the form guides. Otherwise, we need to write the logic on field level if we are planning to design forms which will have form guides developed in future. adobe came with a different concept for these problems using Data Model in ES2. I need to explore on how this works.