example.cs

from user in _dbContext.Set<User>().AsNoTracking()
where user.Id == userId
let name = $"{user.FirstName} {user.LastName}"
let hasFirstName = !string.IsNullOrEmpty(user.FirstName)
let hasLastName = !string.IsNullOrEmpty(user.LastName)
select new
{
    user.Id,
    Name = name,
    ProfileComplete = hasFirstName && hasLastName
}