We can enable cross-account access while creating an AWS connector as per the doc.
This article intends to clarify how the AWS connector behaves once the cross-account access option is enabled.
We would usually configure Cross account role ARN as the IAM role in the target AWS account though we can use this option to establish trust between roles in the same account as well.
Once the cross-account option is enabled and configured with a role in the target account, the credentials used in this connector will always assume the role in the target account. However, we can not use this connector to access the resources in the local account.
If you want AWS connector to access the resources in the local account, you would either need to create another AWS connector without enabling cross-account access or enable cross-account access in the AWS connector with a role created in the local account.