Refer to Priority Flag if Column item is not unique

[gustavo2]

Hello,
I would like to filter the data in Looker based on the price per city.

For example: the result should be City A, City B, City C and City D and their prices.
The challenge I have been facing is that City A and City D are not unique. for that it should refer to the Priority Table Column, where price 1.50 € has priority for City A and therefore the 1€ for City A should not be displayed (filtered out).

Cities with single values should be shown regardless.

Is there a dimension or something in LookML I am missing?

I don’t seem to be able to use the OR filter effectively or to filter our the Priority Table ‘No’ altogether as it would remove City B and City C.

Any thoughts?