Data Lookup for Last 4 Weeks

I'm currently trying to figure out a way that will allow me to compare data from the last week vs the last 4 weeks prior. It also has to be possible to choose an older week and look at the four weeks prior to that date as well.

I have created a dummy version of how I would (ideally) want it to appear with some dummy data but I have no idea how to be able to do it - I'm not able to use Pivot tables in this instance.

Data Lookup Question.xlsx

see the attached file

Try these,

B6,

=SUMIFS(Data!C:C,Data!$A:$A,LEFT($C$2,FIND(" ",$C$2,7))&TEXT(RIGHT($C$2,2)-1,"00"),Data!$B:$B,$A6)

and copy to C6 & E6. Change red highlighted column reference to E:E & F:F in C6 & E6

=SUM(SUMIFS(Data!C:C,Data!$A:$A,LEFT($C$2,FIND(" ",$C$2,7))&TEXT(RIGHT($C$2,2)-{1,2,3,4},"00"),Data!$B:$B,$A6))

and copy to G6 & I6. Change reference to E:E & F:F