Count based on condition

Hi elguestca1 ,

I'm sorry, but because you have two tables and the table relationships are many-to-many, the feature is not possible in this case. I can only manually merge the two tables you give into one table and then use DAX to calculate them.
Then I need to correct one mistake you made in the issue you asked, id 95525 should count as 0 instead of 1 the same as id 99046:

I created a slicer based on the ID:

You can use the following DAX to create a measure:

CountID = 
CALCULATE(
    COUNTROWS('Table3'),
    NOT(ISBLANK('Table3'[Max Date])),
    NOT(ISBLANK('Table3'[First Date])),
    'Table3'[Max Date] > 'Table3'[First Date],
    'Table3'[ID] IN VALUES(Table3[ID])
)

And the final output is shown in the following figure:

Then I strongly discourage you from using a many-to-many relationship, it has a lot of limitations, you can choose to merge two tables manually, or you can add a bridge table to optimize many-to-many relationships, you can refer to the following documents:
Many-to-many relationships in Power BI Desktop - Power BI | Microsoft Learn
Many-to-many relationship guidance - Power BI | Microsoft Learn

Best Regards,

Dino Tao

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