Dynamic Parameter with values based on selected value through the slicers

Hi anmoltripathi5 ,
It is better to provide representative data and expected output t get exact soluion.

However, as I understand that you want a solution to list distinct countries which are not in the selected product. If this is the case then you need a disconnected table of distinct product which will be used in slicer.

See example date based on your discription. Data source image:

Created disconnected table of distinct product for to use in slicer field, see image:

No relationship between the table.

Placed the product from Distinct Product table in slicer. See image:

Now create a measure to list all the distinct country separated by comma which are not the country of selected product.

Try this code to create measure:

DistinctCountriesNotInSelectedProduct = 
VAR SelectedProduct = SELECTEDVALUE('Distinct Product'[Product])
VAR AllCountries = DISTINCT('DataSource'[Country])
VAR CountriesInSelectedProduct = CALCULATETABLE(
    DISTINCT('DataSource'[Country]),
    'DataSource'[Product] = SelectedProduct
)
RETURN
CONCATENATEX(
    EXCEPT(AllCountries, CountriesInSelectedProduct),
    [Country],
    ", "
)

Place this in card and you are done. See output image:
When no selection is made:

When selected Product 1:

When selected Product 2:

Hope this helps!!

If this solved your problem, please accept it as a solution and a kudos!!

Best Regards,
Shahariar Hafiz