Variance Matirx last entry to first entry

[finavon1]

I would like to be able to look at variance from last week and the first entry but not sure how to do this 

[amitchandak]

@finavon1 , if you need week on week then refer

Have these new columns in Date Table, Week Rank is Important in Date/Week Table

Week Rank = RANKX('Date','Date'[Week Start date],,ASC,Dense)
OR
Week Rank = RANKX('Date','Date'[Year Week],,ASC,Dense) //YYYYWW format

These measures can help
This Week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])))
Last Week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])-1))

Power BI — Week on Week and WTD
https://medium.com/@amitchandak.1978/power-bi-wtd-questions-time-intelligence-4-5-98c30fab69d3
https://community.powerbi.com/t5/Community-Blog/Week-Is-Not-So-Weak-WTD-Last-WTD-and-This-Week-vs-La...
https://www.youtube.com/watch?v=pnAesWxYgJ8
Time Intelligence, Part of learn Power BI https://youtu.be/cN8AO3_vmlY?t=27510