@vaibhav__sharma
You can do it with the help of PackageManager.
1. First of all, You need to write some XPATH queries (or else you can choose SQL, SQL-2 whichever suits you).
2. With the help of the queries, you can find the custom group present inside the CRXDE.
3. Get those all the paths found in the result by verifying all the nodes and use the same path inside the filter section of the Package Manager.
4. Creating a package is the easiest way to migrate your users from one instance to another one, also you get a chance to verify the details about all the nodes like rep:policies which are very important while migrating contents.
Hope this will help you 🙂 .