DAX - Avoid Context transition in iterator

Hi,

I am trying to optimize a DAX measures. I have following measure (just added partial - only the virtual table section) where I could see "Context transition in iterator" problem and I was trying to avoid but not able to do.

VAR tab1 =
ADDCOLUMNS (
SUMMARIZE (
ALLSELECTED ( 'FT' ),
'FT'[C1_RGN],
'FT'[C2_RGN_RTLR],
'FT'[B1_VALUE],
'FT'[S1_VALUE],
'FT'[PCK],
'FT'[C_PACKS]
),
"y", ( [test])
)

and 

test = CALCULATE (
SUM ( 'FT'[Y_AMT] ),
ALLSELECTED (
'FT'[PCK_VALUE],
'FT'[S1_VALUE],
'FT'[S2_VALUE],
'FT'[B1_VALUE],
'FT'[S1_VALUE],
'FT'[LCL_PCK],
'FT'[C_PACKS]
)

Here "y" is referring another measure which has different context and scope. How to avoid Context transition in iterator in this case?