How to create user-defined hierarchy for external organization

Summary:

I created a user-defined hierarchy like Country>Area>Organization for an external organization, but the organization is being displayed under the "Unassociated" area.
Could someone please point out where the issue might be in the attached file?

The external source system code is 'EXT1' and organization code is 'P1'. I tried both LEVEL_MEMBER_VALUE=P1 and EXT1:P1, but neither of them worked.

Please note the DIMENSION_NAME and LEVEL_NAME are written in Japanese and mean 'Organization'.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

24A