How does Google SOAR decide whether a entity is internal or external?

[MarinusC]

Hello all, 

we are struggeling with the "IsInternalAsset" entity configuration. 
We mapped a field in the ontology configuration to "DestinationDomains", which in my opinion should be an external Entity.
However, if you open a “DestinationDomains” entity in a case, it will appear as “IsInternalAsset” = “True”.
Can anybody help or knowns how to configure an entity as internal or external?

Thanks a lot!

Some screenshots: