DynamicLinq build select with subquery

I dynamically build select with System.Linq.Dynamic.Core. I want to add another column (subquery). Is this possible?

I need to get same results as this query:

var test = this.DbContext.Countries.Select(t => new
{
    t.Id,
    t.ISOCode,
    lookup = t.Translates.Where(t2 => t2.LangISOCode=="ENG").Select(t2 => t2.Title).FirstOrDefault()
}).ToArray();

I get this far:

this.DbContext.Countries.Select("new(Id,ISOCode)").ToDynamicArrayAsync()

but not sure how to add additional subquery column.