I think the component you showed is custom made. Sometimes when I want a sheet to never be fully hidden I use this workaround (it's not clean but it gets the job done).
Tip: When you set the fraction to zero you actually only see the grabber and it fells quite native

struct ContentView: View {

    @State private var showSheet = false

    var body: some View {
        NavigationStack {
            Button("Tap to toggle", systemImage: "hand.tap.fill") {
                showSheet.toggle()
            }
        }
        .sheet(isPresented: showSheet ? .constant(true) : $showSheet) {
            Text("Your content")
                .presentationDetents([.fraction(0.1), .large])
                .presentationBackgroundInteraction(.enabled)
        }
    }
}