User Input text parameter to update formulas

Hi, Anonymous 

Based on your description, I created data to reproduce your scenario. The pbix file is attached in the end.

You may create a parameter in Power Query as below.

You may create two measures as below in Power BI Desktop.

Frequency = 
COUNTROWS(
    FILTER(
        ALL('Table'),
        CONTAINSSTRINGEXACT([Text],MAX(ParameterText[ParameterText]))
    )
)

First mentioned = 
CALCULATE(
    MIN('Table'[Date]),
    FILTER(
        ALL('Table'),
        CONTAINSSTRINGEXACT([Text],MAX(ParameterText[ParameterText]))
    )
)

You may click 'Transform data'=>'Edit Parameter' and then click 'Refresh' button to update the parameter's value.

ParameterText="word":

ParameterText="value":

Best Regards

Allan

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