Partial Deploy Business Process Flow stages to a Solution

Hi Everyone,

We have a requirement where we need to partial deploy Business Process Flow stages to production environment from Dynamics 365 CRM sandbox environment.

We can easily create Un-managed Solution of a complete "Business Process Flow" to get deploy on production.

Let say we have 5 stages in a "Business Process Flow" and out of 5 we want to use only 2 initial stages to get deploy on production, then How we will achieve this. Please suggest? 

Any suggestion/ help would be highly appreciated.

Thanks

Kavita