We have a dashboard and it has 3 inputs Date, Transaction dropdown, Submit Button. I’m looking to add a dropdown (Manager) between date and transaction dropdown so that I can only see the transactions based on the Manager.
It sounds like you want to use the value of your manager input token in the search that generates the results for the transaction input. I can't tell you how exactly to do it on your dashboard since I don't have your code, but it involves having the manager token in the query of the transaction input, the same way you have it in the main search that creates your results (table or view or whatever you got).
You need to make sure that the tokens work in both searches of course.