Depends on in a doctype descendants of condition

Hi Community

I wanted to use a custom section in item doctype which depends on a item group.
But this evaluation is item group is a descendants of checking.

For example If Item Group is
Purchase

Tier 1

Group 1
Group 2

I wanted to show the section (in item doctype) if the item group is descendants of Tier 1

How to achieve this

Regards
Santhosh