Merging data from multiple CDOs

Is there any workaround for merging the data from two CDOs? The custom objects are the destinations for two import calls from SFDC, so they are constantly being updated. We have the first one mapped to contacts/accounts based on Contact ID or Account ID, so it can be used for filtering in segments. The second one retains data from an SFDC object that does not have any information about contacts/accounts but extended information for the first one.

Now, both CDOs include the Opportunity ID field.

An insight report is not a solution because our goal is to be able to segment based on the information included in the second CDO, the one with no linkage.