How to make sure bot task executes only once after other bot tasks have executed?

Hello, I have a business process with four bot tasks connected together. The first three take in 10 input records and pass them along as output to each other. The third bot task adds the results to a data store using OrmLiteRepository.

The final bot task takes in records from the data store but I want it to run only once and only after the other three bot tasks have finished. How do I accomplish this? Thank you very much.