I am trying to do an If/Then referencing another row

Expanded explanation--

In this data I want to do something like:

if team on row a = team on row b

and end of week on row a = end of week on row b - 7

then put the net change amount from row a into a field named 'running total' on row b

I am trying to write the following:
If the field PriorWeek in this row equals the EndDate in another row, put in the NetAmount from the other row as PriorAmount.
ie:  if the Net Amount for 5/1/20 is 50, put that as PriorAmount in the row for 5/8/20