Need Help with ISFILTERED multiple selections

let me rephrase my issue.

I am using a parent child hirerchy in a matrix visual. A parent has multiple children.

Consider a table as item_code, Item_name & item_description.

in the Matrix visual hirerchy we can just see the item names. When we click any item we have to see the item_code in the card.
When i select one item i can get the item_code in the card
but when i click the parent item the entire parent child records are being selected and we get a blank in the card. Instead can we have something like this...
1) When we click the parent only the parent id will be displayed in the card, it should not consider the selection of other records... OR
2) we can say if we select multiple records only the first record id should be displayed. how can we achive this ? Kindly suggest.

I used the below measure :  

Id = IF(ISFILTERED(‘item_table'), SELECTEDVALUE('CUSTOM VIEW'[item_ID]), "PLEASE SELECT ITEM")