how to create calculation view on table view in hana?

Hi Expert

There is a default table view called NSDM_V_MARD, in catalog->user->views folder of hana studio 2.2

Here is the definition of that view...

CREATE VIEW "SAPABAP1"."NSDM_V_MARD" ( "MANDT",

  "MATNR",

  "WERKS",

  "LGORT",

  "LABST",

  "FSH_SALLOC_QTY_S" ) AS SELECT

  "T"."MANDT",

  "T"."MATNR",

  "T"."WERKS",

  "T"."LGORT",

  "T"."PSTAT",

  "T"."LVORM",

  CASE WHEN ( "M"."GJPER" = N'0000000'

  OR "M"."GJPER" IS NULL )

THEN "T"."LFGJA"

ELSE ( RTRIM( SUBSTRING( "M"."GJPER",

  1,

  4 ) ) )

END AS "LFGJA",

  CASE WHEN ( "M"."GJPER" = N'0000000'

  OR "M"."GJPER" IS NULL )

THEN "T"."LFMON"

ELSE ( RTRIM( SUBSTRING( "M"."GJPER",

  6,

  2 ) ) )

END AS "LFMON",

  "T"."SPERR",

  "M"."LABST",

  N'X' AS "MDRUE",

  "T"."MDJIN",

  "T"."FSH_SALLOC_QTY_S"

FROM "MARD" "T"

LEFT OUTER JOIN "NSDM_V_MARD_DIFF" "M" ON ( "T"."MANDT" = "M"."MANDT"

  AND "T"."MATNR" = "M"."MATNR"

  AND "T"."WERKS" = "M"."WERKS"

  AND "T"."LGORT" = "M"."LGORT"

  AND "T"."MANDT" = "M"."MANDT" ) WITH READ ONLY

Now I want to make a calculation view on top of this view so that bo design studio can consume that view.

Thanks.