Create array of values from a dictionary of array of objects filtered by property

I have a dictionary where key is string and value is array of objects:

objDict = {
  dataset1: [ { id: 1, count: 6 }, { id: 2, count: 7 }, { id: 3, count: 8 } ],
  dataset2: [ { id: 1, count: 5 }, { id: 2, count: 4 }, { id: 3, count: 3 } ]
}

I need to filter objects with specific id and create an array of count values: for id = 2 it would be countArray = [ 7, 4 ].
I suppose I should first use Object.values(objDict) but I don’t know what to do afterwards.