Assuming the product has an API and you have or can get someone with programming skills, you could connect to that API and use the Tableau API to generate an extract.
It wouldn't be a live connection obviously.
Hi Arpit -
Why you export your data out of DFP using the process recommended by DoubleClick?:
After you do that, you can use Tom's suggestion to use our extract API or just import the text files into Desktop as extacts...
If you use data transfer to get DFP data, there is a way to push this data into Google Cloud Platform's BigQuery which you can use Tableu on top of.