This should help get you started at least, but you'll need SQL Server 2012. You didn't specify the version you're using.
declare @t table (id int, name varchar(50), value varchar(50), HasParent varchar(3), ParentID int, HasChild varchar(3))
insert into @t
exec dbo.YourStoredProc
select
id
, name
, value
, HasChild 'attributes.HasChild'
, HasParent 'attributes.HasParent'
, ParentID 'attributes.ParentId'
, child.id 'children.id'
, child.name 'children.name'
, child.value 'children.value'
, child.haschild 'children.attributes.haschild'
, child.hasparent 'children.attributes.hasparent'
, child.parentid 'children.attributes.parentid'
, gchild.id 'children.children.id'
, gchild.name 'children.children.name'
, gchild.value 'children.children.value'
, gchild.haschild 'children.children.attributes.haschild'
, gchild.hasparent 'children.children.attributes.hasparent'
, gchild.parentid 'children.children.attributes.parentid'
from @t t
join @t child on child.ParentID = t.id
join @t gchild on gchild.ParentID = child.id
for json auto