Data grouping based on second table

Hi Mike1309

I have understood about your problem, here is the solution I offer:

Here are the data of the two tables, you can check the date type, here it is recommended to use the (m/d/yyyy) format

Create a  measure, you can match the period by judging the country name and date range.

result = var invoiceDate = SELECTEDVALUE(invoices[invoice date])
 var invoiceCountry = SELECTEDVALUE(invoices[country])

 RETURN CALCULATE(
        MAX(periods[period]),
    FILTER(periods, 
        periods[country] = invoiceCountry && 
        periods[start day] <= invoiceDate &&
        periods[end day] >= invoiceDate))

Here is the result, and you can add slicers to filter

Best Regards,

Nono Chen

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