Query the "user security" settings given to a folder by query builder

Hello,

I'm using query builder to extract the objects saved in CMC, and I would like to know how can I obtain the user security give to a folder.

When I query (SELECT * FROM CI_INFOOBJECTS WHERE SI_KIND='Folder'), it returns the SI_ROLES_ON_OBJECT given to the folder, but it says nothing about the User Group.

When I query (SELECT * FROM CI_SYSTEMOBJECTS WHERE SI_KIND='CustomRole'), it returns the SI_OBJECTS_ASSIGNED_ROLE folders that have been granted that role, but it says nothing about the User Group.

And when I query (SELECT * FROM CI_SYSTEMOBJECTS WHERE SI_KIND = 'UserGroup'), it returns the hierachy within the UserGroup is contained, but it says nothing about the Folders or Roles.

How can I relate all these three objects? Folder, UserGroup and CustomRole

Thanks in advance!

Rafael.