LAG FUNCTION DAX

Zaynah16 , You need time intelligence with date table and additional filter

Power BI — Year on Year with or Without Time Intelligence
https://medium.com/@amitchandak.1978/power-bi-ytd-questions-time-intelligence-1-5-e3174b39f38a
https://www.youtube.com/watch?v=km41KfM_0uA

example

YTD Sales BP= CALCULATE(Countrows(Table),DATESYTD('Date'[Date],"12/31"), filter(Table, Table[Market] = "BP" ))
Last YTD Sales BP = CALCULATE(Countrows(Table),DATESYTD(dateadd('Date'[Date],-1,Year),"12/31"), filter(Table, Table[Market] = "BP" ))

YTD Sales WP= CALCULATE(Countrows(Table),DATESYTD('Date'[Date],"12/31"), filter(Table, Table[Market] = "WP" ))
Last YTD Sales WP = CALCULATE(Countrows(Table),DATESYTD(dateadd('Date'[Date],-1,Year),"12/31"), filter(Table, Table[Market] = "WP" ))