SAP HANA CDS TABLE/ENTITY Calculated field not able to use in Calculation View

I have created X.hdbdd entity which has following fields

namespace ABC.LANDING.XYZ;
@Schema: 'CUSTOM'
@Catalog.tableType: #COLUMN
entity XYZ_DL_NW  {
	KEY A : String(3) not null;
	KEY B : Integer64 not null;
	KEY C : UTCTimestamp not null;
	KEY D : String(5) not null;
	Y : Integer;
	Z : Integer;
    YZ : Integer = "Y" - "Z";
	
	};

In Calculation view when I use calculated field YZ (which is YZ : Integer = "Y" - "Z" from X.hdbdd entity), I am getting following error

As of now the workaround which I have done is creating Table Function and then utilizing it in calculation view.

Is there any solution or any reason why I am not able to use aforesaid calculated field directly in Calculation view??