Calculate correct overall summary revenue in DAX

I have a table of data which I need to create pivot reports from, each line of data is all set out as per example below:

PowerPivot to find specific text

I need to find specific text in a column in PowerPivot but the field is sometimes spelt incorrectly.

PowerPivot extract text after different characters

I need to extract text after different delimiters.

PowerPivot change Total depending on date range thats selected

I have a table as per below:

Previous Week Duration Sum PowerPivot

I need to get the previous week sum total in a column on PowerPivot.