Optional dynamic grouping by many using linq

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LINQ

grouping

Hi,
I am facing a problem with dynamic grouping.
I have a requirement where buttons are draggable for grouping for generating report

I tried using dynamic linq.I don't want to use magical string.

So I decided to take more time and get something without using strings.

I found C# 6.0 in a Nutshell - PredicateBuilder[^] and
other extension c# 3.0 - How can I hierarchically group data using LINQ? - Stack Overflow[^]

But GroupByMany in extension has delegate as function not expression.

So I could not try like

<pre lang="c#"><pre lang="c#"><pre lang="text">

foreach (var entry in resultEntries)
           {
               if (projectGroup)
                   predicate1 = predicate.And(p => p.Project.Id == entry.Project.Id);

               if (clientGroup)
                   predicate2 = predicate.And(p => p.Client.Id == entry.Client.Id);

               if (userGroup)
                   predicate3 = predicate.And(p => p.User.Id == entry.User.Id);

               predicateResult.And(predicate1);
               predicateResult.And(predicate2);
               predicateResult.And(predicate3);

}

var output  = resultEntries.GroupByMany(predicate);

Ex:Hardcoded type for one scenario looks like

var nestedGrouping = reportTimeEntries
                               .GroupByMany(t => t.Project.Id, t => t.Client.Id);

I want this to be dynamic.Because I don't know the order in which filter are sent for grouping.

Please help me.I am stuck from past three weeks.

What I have tried:

public enum eEntry
{
NotSet = 0,
[Description="Clients"]
Clients = 1,
[Description="Projects"]
Projects = 2,
[Description="Users"]
Users=3
}


public void SubmitReport(EntryFilter filter){//filter contain reportGroups and date range
var reportGroups="Projects,Clients";//actually should come from filter.But I am showing one scenario
//Note: reportGroups can be 1.Clientslients,
// 2.Projects,
// 3.Users,
// 4.Clients,Projects,
// 5.Projects,Clients
// 6.Clients,Users,
// 7.Users,Clients,
// ..... etc. with all possible combinations including optional

//Above are used for GROUPING MY ENTRIES
List<entry> entries=services.getEntries();

//I want to group by IDs of reportGroups
var projectGroup = reportGroups.Contains(eEntry.Projects);
var clientGroup = reportGroups.Contains(eEntry.Clients);
var userGroup = reportGroups.Contains(eEntry.Users);

if (projectGroup)
entries.GroupBy(e=>e.Project.Id);

if (clientGroup)
entries.GroupBy(e=>e.Client.Id);

if (userGroup)
entries.GroupBy(e=>e.User.Id);
// and all other combinations possible

}