import Foundation

let items = (1...10).map { _ in
 (weight: Int.random(in: 1...10), value: Int.random(in: 1...10))
}
let vals = Dictionary(grouping: items, by: {$0.weight})
 .mapValues{$0.map{$0.1}}
 .map{ item in
 (weight: item.key, value: item.value.filter{
 $0 >= item.key
 })
 }
 .filter{!$0.value.isEmpty}
 .sorted{$0.weight < $1.weight}
 .map{($0.weight, $0.value.sorted{$0 > $1})}

print(vals)

error: the compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions
    .map{($0.weight, $0.value.sorted{$0 > $1})}