So, you don't want the filter to be source_new=JustEat, but rather an ID filter set to include the 876 IDs in that source_new=JustEat category.
While I know you can do this manually with a filter on ID and either:
- Ranking type, TOP 10000, fx: IF ( ( DUPCOUNT( [Source_new] ) , [Source_new=JustEat] ) > 0 , 1 , NULL )
- Advanced type:
{ "attributes": [ { "dim": "[TABLE NAME.Source_new]", "filter": { "members": [ "JustEat" ] } } ], "custom": true }
I don't know a way to go from a "Select/Click" filtering of that column in the widget output to a filter like one of the above.