var PersonalFieldBoundary = await _medicalDbContext.PersonalFieldBoundaries.Include( x=>x.FieldBoundary)
                                                                                        .AsNoTracking()
                                                                                        .Where(x => x.ParticipantId == participantId && x.Start <= insertDate)
                                                                                        .GroupBy(x => new { x.FieldBoundaryId })
                                                                                        .Select(x => x.OrderByDescending(x => x.Start)
                                                                                        .Take(1))
                                                                                        .SelectMany(x => x)
                                                                                        .ToListAsync();


            return PersonalFieldBoundary; 

            var PersonalFieldBoundary = await _medicalDbContext.PersonalFieldBoundaries.Include( x=>x.FieldBoundary)
                                                                                        .AsNoTracking()
                                                                                        .Where(x => x.ParticipantId == participantId && x.Start <= insertDate)
                                                                                        .GroupBy(x => new { x.FieldBoundaryId })
                                                                                        .Select(x => x.OrderByDescending(x => x.Start)
                                                                                        .Take(1))
                                                                                        .SelectMany(x => x)
                                                                                        .ToListAsync();


            return PersonalFieldBoundary;