❔ Help with linq query

c#        
var getOneGroup = CustList.GroupBy(x => new
{
  x.Address,
  x.SomeData
})
.Select(x => x.FirstOrDefault(y => y.SomeData.Equals("Klepto"))).ToList();

Customer cust1 = new Customer()
{ Name = "Cust1", Number = "7784875", Address = "Address1", SomeData = "Klepto" };
Customer cust2 = new Customer()
{ Name = "Cust2", Number = "7574477", Address = "Address2", SomeData = "Great Kisser" };
Customer cust3 = new Customer()
{ Name = "Cust3", Number = "7680611", Address = "Address1", SomeData = "Klepto" };
Customer cust4 = new Customer()
{ Name = "Cust4", Number = "76800802", Address = "Address4", SomeData = "Good" };
Customer cust5 = new Customer()
{ Name = "Cust5", Number = "7777777", Address = "Address5", SomeData = "Funny" };