max sales based on only category

Hi powerbiexpert22 ,

Please try this measure:

Max Sales = 
    MAXX( 
        FILTER(
            SUMMARIZE(
                ALLSELECTED('Orders'),
                'Orders'[Category],
                'Calendar'[Month]
            ),
            'Orders'[Category]=SELECTEDVALUE('Orders'[Category])
        ),
        [TSales]
    )

Best Regards,
Gao
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

How to get your questions answered quickly --  How to provide sample data in the Power BI Forum -- China Power BI User Group