How to sum when filter is based on the row

1) You need to close the REMOVEFILTERS argument with a ")" after your 'Invoices' table.

INCORRECT: REMOVEFILTERS(Invoices, Invoices[Productgroup...))

CORRECT: REMOVEFILTERS(Invoices), Invoices[Productgroup...)

2) You need to check where Invoices[Productgroup& FYM] = _CurrentGroup (which is a VAR), rather than Invoices[VAR_group], which looks like a 'table'[column].

3) In the screenshot of your measure, it looks like you're just starting with the CALCULATE, rather than declaring the variables needed.

Please try to follow the same structure of the measure provided.

4 VARS, followed by a RETURN.

Regards,

Nathan