public static ArrayList<ContentType> getPossibleParentContentType(ContentType content){
		
		Web web = ((Web)((CustomList)content.eContainer()).eContainer());
		while(web.eContainer().eClass().getName().equals("Web")){
			web = (Web) web.eContainer();
		}
		ArrayList<ContentType> allContentTypes = new ArrayList<>();
		
		allContentTypes = returnAllContentTypeFromGivenWeb(web, allContentTypes);
		
		
		allContentTypes.remove(content);
		
		return allContentTypes;
	}

Grammar:
CustomList returns CustomList:
	'CustomList'
	name=QualifiedName
	'{'
	'guID' '=' guID=STRING
	'displayName' '=' displayName=STRING
	'type' '=' type=ListType
	('description' '=' description=STRING)?
	(ownedContentType+=ContentType (ownedContentType+=ContentType)*)?
	(ownedView+=View (ownedView+=View)*)?
	'}';
ContentType returns ContentType:
	'ContentType'
	name=QualifiedName
	'{'
	'guID' '=' guID=STRING
	'displayName' '=' displayName=STRING
	('description' '=' description=STRING)?
	('group' '=' group=STRING)?
	('parent' '=' parentContentType=[ContentType|QualifiedName])?
	(ownedField+=Field (ownedField+=Field)*)?
	'}';

public class ContentModelScopeProvider extends AbstractDeclarativeScopeProvider {
	IScope scope_ContentType_parentContentType(final ContentType ctx, EReference r) {
		final EObject parent = ctx;
		
		//System.out.println("parennnnnnnnnnnnnnnnnttttttttttttttttt"+parent);
		final ArrayList<ContentType> possiblecontenttype = ContentTypeUtil.getPossibleParentContentType(ctx);
		//System.out.println("possible"+ possiblecontenttype);
		
	return new FilteringScope(delegateGetScope(ctx, r), new Predicate<IEObjectDescription>() {
		public boolean apply(IEObjectDescription d) {
			System.out.println("........................."+d.getName().toString());
		return possiblecontenttype;  //I receive an error because not returns 
		};
		});
	}
		
	
	
}

public static ArrayList<ContentType> getPossibleParentContentType(ContentType content){
		//Oncelikle rootWeb bulunur Buradanda tüm ContentTypelar cekilecek.
		Web web = ((Web)((CustomList)content.eContainer()).eContainer());
		while(web.eContainer().eClass().getName().equals("Web")){
			web = (Web) web.eContainer();
		}
		ArrayList<ContentType> allContentTypes = new ArrayList<>();
		//Burada Dokumandakı tum ContentTypelar cekilir.
		allContentTypes = returnAllContentTypeFromGivenWeb(web, allContentTypes);
		
		//Burada kendi dışındaki contentTypeları getirip seçmesini isterim.
		allContentTypes.remove(content);
		
		return allContentTypes;
	}
	
	public static ArrayList<ContentType> returnAllContentTypeFromGivenWeb(Web rootWeb, ArrayList<ContentType> returnAllContentTypesFromWeb){
		
		EList<CustomList> ownedLists = rootWeb.getOwnedList();
		for (Iterator<CustomList> iterator = ownedLists.iterator(); iterator.hasNext();) {
			CustomList customList = (CustomList) iterator.next();
			EList<ContentType> ownedContentTypes = customList.getOwnedContentType();
			
			for (Iterator<ContentType> iterator2 = ownedContentTypes.iterator(); iterator2
					.hasNext();) {
				ContentType contentType = (ContentType) iterator2.next();
				returnAllContentTypesFromWeb.add(contentType);
			}
		}
		
		EList<Web> ownedWebs = rootWeb.getOwnedWeb();
		
		for (Iterator<Web> iterator = ownedWebs.iterator(); iterator.hasNext();) {
			Web web = (Web) iterator.next();
			returnAllContentTypeFromGivenWeb(web, returnAllContentTypesFromWeb);
		}	
		return returnAllContentTypesFromWeb;
	}
}

public class ContentModelScopeProvider extends AbstractDeclarativeScopeProvider {
	IScope scope_ContentType_parentContentType(final ContentType ctx, EReference r) {
		final EObject parent = ctx;
		
		//System.out.println("parennnnnnnnnnnnnnnnnttttttttttttttttt"+parent);
		final ArrayList<ContentType> possiblecontenttype = ContentTypeUtil.getPossibleParentContentType(ctx);
		return Scopes.scopeFor(possiblecontenttype );
	}
		
	
	
}

IScope scope_Lookup_contenttype(final ContentType ct, EReference r) {
		//final EObject parent = ctx;
		
		//System.out.println("parennnnnnnnnnnnnnnnnttttttttttttttttt"+parent);
		final ArrayList<Field> possiblefield = LookUpUtil.returnSourceContentTypeNotLookUpFields(ct);
		//System.out.println("possible"+ possiblecontenttype);
		
		return Scopes.scopeFor(possiblefield);
	
		
		
		
	}

public class LookUpUtil {
	
	public static EList<Field> returnSourceContentTypeFields(ContentType contentTarget){
		return contentTarget.getOwnedField();
	}
	
	public static ArrayList<Field> returnSourceContentTypeNotLookUpFields(ContentType contentTarget){
		EList<Field> ownedFields = contentTarget.getOwnedField();
		ArrayList<Field> fields = new ArrayList<Field>();
		for (Iterator<Field> iterator = ownedFields.iterator(); iterator.hasNext();) {
			Field field = (Field) iterator.next();
			if(!field.eClass().getName().equals("LookUp")){
				fields.add(field);
			}
		}
		return fields;
	}
}