How to keep/exclude a particular package path when using proguard?

You don’t specify in what way it doesn’t work. Your configuration keeps the names of all public classes in the specified package:

-keep public class com.myapp.customcomponents.*

The following configuration keeps the names of all public classes in the specified package and its subpackages:

-keep public class com.myapp.customcomponents.**

The following configuration keeps the names of all public/protected classes/fields/methods in the specified package and its subpackages:

-keep public class com.myapp.customcomponents.** {
  public protected *;
}