Dax measure

[anmolmalviya05]

I have below sample data 

I want to create a dax measure which return the sum of values between each new entry,
for example:  before the first entry in entry column it should return 0, after the first entry in entry column it should return the sum of all values upto next entry
expected output:

[lbendlin · Accepted solution]

This is a very heavy lift for a DAX measure.  Would be much easier to do in Power Query

Expected Output =
VAR i =
    SELECTEDVALUE ( 'Table'[Index] )
VAR minindex =
    MAXX (
        FILTER ( ALLSELECTED ( 'Table' ), [Index] <= i && [Entry] > 0 ),
        [Index]
    )
VAR maxindex =
    COALESCE (
        MINX ( FILTER ( ALLSELECTED ( 'Table' ), [Index] > i && [Entry] > 0 ), [Index] ),
        1 + MAXX ( ALLSELECTED ( 'Table' ), [Index] )
    )
RETURN
    IF (
        i = 1,
        0,
        SUMX (
            FILTER ( ALLSELECTED ( 'Table' ), [Index] >= minindex && [Index] < maxindex ),
            [Value]
        )
    )