How to show single value with interaction between visuals and max value?

Hi cheid_4838 ,

Thanks for posting your question in Microsoft Fabric Community.

I reproduced the scenario using the sample structure you described. 

The approach shared earlier by Sandip_Palit using the Show Mechanic for Max Hours measure works correctly when evaluated in the row context of the mechanics visual. I followed that logic but slightly adjusted the setup to handle both cases: when a component is selected and when nothing is selected (so all rows show by default).

To achieve the behavior where selecting a row in the Components table filters the Mechanic table to show only the record with the matching max labor hours, you can use the following measure:

SelectedComponentMaxHours = 
CALCULATE (
    MAX (ComponentLabor[Max Labor Hours]),
    ALLEXCEPT (ComponentLabor, ComponentLabor[ComponentDesc])
)

Then use this filter measure on your mechanic visual:

ShowOnlyMaxMechanic = 
VAR _SelectedMax =
    CALCULATE (
        MAX (ComponentLabor[Max Labor Hours]),
        ALLEXCEPT (ComponentLabor, ComponentLabor[ComponentDesc])
    )

VAR _IsFiltered =
    ISFILTERED (ComponentLabor[ComponentDesc])

RETURN
    IF (
        NOT _IsFiltered || MAX(MechanicLabor[Max Labor Hours]) = _SelectedMax,
        1,
        0
    )

Apply ShowOnlyMaxMechanic = 1 as a visual-level filter on the mechanic table visual. This ensures that when a component is selected, only the mechanic(s) with matching max labor hours will show, and when no selection is made, all rows will be visible.

Result:
Without selection:

When selected:

Attached is the .pbix for reference.

Thanks Sandip_Palit for your suggestions and approach.

Hope this helps. Please reach out for further assistance.

Thank you.