Nested GroupBy in c# Xamarin.forms

I need to create a var for nested groupby items

Data Set :
Item : grocery dop : 01/Jan/2019 Value : 2000 rs
Item : cell dop : 04/Mar/2019 Value : 10000 rs
Item : clothes dop : 05/Jan/2019 Value : 15000 rs
Item : Veggies dop : 06/Jan/2019 Value : 1500 rs
Item : grocery dop : 04/Jan/2019 Value : 1000 rs
Item : Veggies dop : 06/Jan/2019 Value : 200 rs
Item : tea dop : 04/Feb/2019 Value : 10 rs

I need the output like below

for loop (monthwise)
Jan Month in a grouped var based on Item Name
Item : clothes dop : 05/Jan/2019 Value : 15000 rs (Highest Value should come first)
Item : grocery dop : 01/Jan/2019 Value : 2000 rs (Same Item name )
Item : grocery dop : 04/Jan/2019 Value : 1000 rs (Same Item name )
Item : Veggies dop : 06/Jan/2019 Value : 1500 rs (Same Item name )
Feb
Item : tea dop : 04/Feb/2019 Value : 10 rs

Mar Item : cell dop : 04/Mar/2019 Value : 10000 rs

var groupListDop = expDetailsList.GroupBy(x => x.Dop.Month);
foreach (var month in groupListDop)
{
foreach (var day in month)
{
//I want here the Item name in a sorted Way } }