Relative filtering: Week before last week

Hi there

I have a time series i.e. a column of decimal numbers next to a column with dates. I would like a card that shows me four big numbers:

- the sum of the last seven days (e.g. 5 September 2018 - 11 September 2018)

- the sum of the previous seven days (e.g. 29 August  2018- 4 September 2018)

- the sum of the last seven days last year (e.g. 5 September 2017 - 11 September 2017)

- the sum of the previous seven days last year (e.g. 29 August  2017- 4 September 2017)

If I use a card with relative date filtering, I can do the last seven days but I don't know how to do the previous seven days or the same things last year.

I thought I would perhaps use a moving sum i.e. a measure that daily works out the sum of the previous seven days but even then, I wouldn't know how to pull the measure seven days ago.

Does anyone know how to resolve this? Thanks a lot for reading.