c# - Optional Random ordered nested grouping in linq -

i in position can't think of answer regarding optional grouping in linq.

basically,i want generate report comes screen having filters. these filters(mostly grouped) optional , can rearranged.it's like

filters: 1.clients projects tasks duration                 or           2.projects clients  tasks duration                 or           3.task duration etc. 

with possible combinations. data should like

1.clienta      projecta         taska              26hrs 45mins         taskb              43hrs 23mins     projectb       taskx...... 2.projecta     clienta        taska              26hrs 45mins...  3.taska       26hrs 45mins   taskb      6hrs 35mins 

i have data.but unable write logic generalized.

i thinking enum hold filters (viewmodel)selected enum.client,enum.project... and

 if (clientgroupchecked)       foreach(var clientgroup in list){         //group list client here      if(projectgroupchecked)         foreach(var projectgroup in clientgroup){         //group list project here } } 

i know,it's wrong.this way have put logic combinations possible.
couldn't think of else.i want generalized because may have more filters added in future , don't want change entire logic filters(of course,i want add new filter group somewhere in logic.but want more easy maintain also.

edited:
@sschimmel :my point grouping can shuffled(for have buttons[selected -->green , unselected-->gray , these buttons movable grouping].
so when writing linq logic,how can know on criteria have group in particular way?
for ex: have columns b c d e f.in this, can choose group or b or b or acb....etc. possible combinations.how achieve this?i don't want if else check because have many possibilities.if 1 more filter added,it have many more possibilities. that's why thinking need of general approach this.

edit 2:

please find attachment , how trying below.

    //for following ,i need way of writing passing right values     var reportgroupingcp = (from t in taskentries                           group t new { clientid,projectid  } g                           select new                            {                               clientid = g.key.clientid,                               projectid = g.key.projectid,                              result = (type)g //what t                           }).tolist();       var reportgroupingce = (from t in  taskentries                           group t new { clientid,employeeid } g                           select new                            {                               clientid = g.key.clientid,                               employeeid = g.key.employeeid,                               result = (type)g //what t                           }).tolist();     //can't use above if there filter client.similarly other cases/i don't want write each one.i need way dynamically.may passing enum or adding ids class or else 

filter 1

filter 2

if understood question correctly, wan't group data dynamically on multiple properties.

the easiest solution use dynamic linq lets create queries strings can compose user inputs.

// userselections created dynamically user selected. var userselections = new[] { "clientid", "projectid" }; var propertiestogroupby = string.join(", ", userselections); var groupeddata  = data.groupby("new(" + propertiestogroupby + ")"); 

it's not type safe nor checked during compile time, easy use , solves problem. it's documented nicely.

i tried come solution dynamically combines expression<func<taskentry, object>>s got stuck on creating expression ìnstantiates anonymous type use inside groupby(new { ... }). because number of selected properties group not known during compile time, it's not possible create anonymous type.