I think he's saying use tabs on lines A, B, and C up until the indentation level (the "int"). Then on line B use spaces for all the whitespace from there until the text is aligned.

    /*t*/int f() {
    /*tabs*/int someVariableName = myFunctionCall(expr(5),          // <--- line A
    /*tabs*//*--------------spaces--------------*/somethingElse(9), // <--- line B
    /*tabs*//*--------------spaces--------------*/a_long * expression + involving(multiple.subExprs));
    /*tabs*/int d = somethingElse; // <-- line C
    /*t*/}