Attribute.cs

	public class FeatureEnabledBoolAttribute : PXDBBoolAttribute
	{
		protected Type RecordType;

		public BCFeatureEnabledBoolAttribute(Type recordType)
		{
			RecordType = recordType;
		}
		public override void CommandPreparing(PXCache sender, PXCommandPreparingEventArgs e)
		{
			//On CommandPreparing the querry will be generated, we need only select, since this is virtual field 
			if ((e.Operation & PXDBOperation.Command) == PXDBOperation.Select && (e.Operation & PXDBOperation.GroupBy) == 0)
			{
				Type bqlTable = sender.GetItemType();
        
        			//Here you can check in any way if you feature is enabled or disabled
				List<String> listOfDisabledRecordTypes = GetListOfDisabledTypesByFeatures();

				//Here we can build a dynamic Swtch/Case that will validate the feature
				SQLSwitch switchExpr = new SQLSwitch();
				if (listOfDisabledFieatures.Count > 0)
				{
					foreach (String type in listOfDisabledRecordTypes)
					{
						switchExpr = switchExpr.Case(
              						new Column(RecordType.Name, bqlTable.Name).EQ(new SQLConst(type)),
              						new SQLConst(false));
					}
				}
				else
					switchExpr = switchExpr.Case(new SQLConst(1).EQ(1), new SQLConst(true));

				switchExpr = switchExpr.Default(new SQLConst(true));

				//Finally assemblying query.
				Query q = new Query().Field(switchExpr);
				e.Expr = new SubQuery(q);
				e.Cancel = true;
				e.BqlTable = bqlTable;
			}
		}
	}

MyDAC.cs

public class MyDAC : IBqlTable
{
    //.........

  		#region IsFeatureEnabled
		public abstract class isFeatureEnabled : PX.Data.BQL.BqlString.Field<isFeatureEnabled> { }
		//Lets use our new attribute on a feield
		[BCFeatureEnabledBool(typeof(MyDAC.recordType)))]
		public virtual bool? IsFeatureEnabled { get; set; }
		#endregion
    
    //.........
}

MyGraph.cs

public class MyGraph : IBqlTable
{
    //.........
    
    //And now we can use our new field anywhere, even in GI.
  	public PXSelect<MyDAC, Where<MyDAC.isFeatureEnabled, Equal<True>>> MyDataView;
    
    //.........
}