Calculations by Rank

Anonymous -

Would the below work for you?

Var = 
VAR nextRank = Table1[Rank] + 1
VAR differnce = 
    CALCULATE(
        VALUES(Table1[Value]),
        FILTER(ALLEXCEPT(Table1,Table1[Type]),Table1[Rank] = nextRank)
    ) - Table1[Value]
RETURN
    IF(
        differnce >= 0,
        differnce,
        BLANK()
    )

Anonymous -

The entire code block is your calculated column. Documentation on using VAR can be found @ https://docs.microsoft.com/en-us/dax/var-dax and a nice example article can be found @ https://www.sqlbi.com/articles/variables-in-dax/

Anonymous -

You're missing closing ' ) ' in a couple places.

Copy -> Paste my code and replace 'Table1' with 'Primary_ID' or try formatting multi-line by clicking ALT + ENTER so you can see your opening and closing Parentheses ' ( ' & ' )' respectively a little easier.