SharePoint does not provide a web service to get Active Directory group information. The only way I'm aware of to get this information in InfoPath is for you to create a custom web service that would provide it.
If you wish to build the custom web service then you should be able to use code similar to the code below to get the
UserPrincipal for the current user. Once you do you can call the
GetGroups method to find out the groups to which they belong.
protected bool CurrentUserIsMemberOfGroup(string groupName)
string userLogin = SPContext.Current.Web.CurrentUser.LoginName;
// To get the right context, run with elevated privileges
var principalContext = new PrincipalContext(ContextType.Domain);
var userPrincipal = UserPrincipal.FindByIdentity(principalContext, System.DirectoryServices.AccountManagement.IdentityType.SamAccountName, userLogin);
var group = GroupPrincipal.FindByIdentity(principalContext , groupName);
For more information on getting information from Active Directory please see Check if a SharePoint user is member of an AD group,
Retrieve the Active Directory groups of the current user, and UserPrincipal Class
For more information on building and deploying a custom web service please see Building a SharePoint-Hosted WCF Service