Primary ID and link id is in same table in sql

I have a table in which Main autoincreament id and its link id is in same table and dont have a saperate table for link as given below

id   linkid    topics
 1     0        algebra
 2     0        maths
 3     1        coordinates
 4     1         xy coordinates
 5     2         numerics
 6     2        statistics

and i worte a procedure as

select topics,
    (select TopicName_en +'~' as [text()] from Topics t2 where  t1.id=t2.linkidfor xml path('')) as subtopics
from Topics t1

and i got result as

topics               subtopics
-------------------------------------------------
algebra               coordinates~xy coordinates
maths                 numerics~statistics
coordinates           null
xy coordinates        null
numerics              null
statistics            null

and my question is how to bind the acordian panel as per the dynamic result im getting