Create a virtual table with Previous date transaction column

Hi ngocrin1 
Actually I did not get the idea of using 'Date'[Date] to obtain the previous date. If you want to get pervious calendar date then simply use

Virtual Table =
ADDCOLUMNS (
    SUMMARIZE ( Sales, Sales[Purchase Date], Sales[Sales Person ID] ),
    "@Revenue", [Sales Revenue],
    "@PreDate", Sales[Purchase Date] - 1
)

If you're looking for the previous sales date of the product in row then please try

Virtual Table =
ADDCOLUMNS (
    SUMMARIZE ( Sales, Sales[Purchase Date], Sales[Sales Person ID] ),
    "@Revenue", [Sales Revenue],
    "@PreDate",
        VAR CurrentDate = Sales[Purchase Date]
        VAR PreDate =
            MAXX (
                CALCULATETABLE (
                    VALUES ( Sales[Purchase Date] ),
                    Sales[Purchase Date] < CurrentDate
                ),
                Sales[Purchase Date]
            )
        RETURN
            PreDate
)