Xcodeproj ruby gem Project.groups not finding all groups

Question

Am using Xcodeproj to iterate through all the groups added in my project. But it seems to only find the groups which are added via Xcode i.e. groups added by right clicking and selecting "New Group" option from menu and fails to find the groups which are added by dragging the folder in the project navigator window.

Here's my code:

def find_group

  project = Xcodeproj::Project.open(xcodeproj_path)

  sources_group = nil

  group_name = 'Resources'

  sources_group = project.groups.find do |group|

    group.name == group_name

  end
end