Yes. In their documentation, Aggregate IQ go into detail about their system. It starts with being bootstrapped by the RNC's Data Trust data vault, which is the Republican National Committee here in the United States. I had actually found the Data Trust database before it was part of the find in June 2017. It's quite extensive. It contains data as they merged with i360, which is a Koch brothers-backed political information company. Data Trust deleted a blog entry where they claim to have merged their data with i360.
There's also L2 Political. They provided data to this whole beast of a machine. That was admitted to on Cambridge Analytica's website recently.
Facebook is obviously part of it. The documentation by AggregateIQ goes on to explain that commercial databases are involved. I know that Experian is one that contributed data toward the RNC Deep Root Analytics data briefs that I found in 2017. I know that because there were Experian IDs being lined up to each voter ID with all the consumer habits being tied onto everybody.
AggregateIQ also states that candidates can bring in their own sources of volunteer and supporter and donator information. They'll aggregate all that into the main “database of truth”, as they call it. State voter files then corroborate what the RNC has on file.
So there's really no end to what they can plug into here.