Use the Creator/Editor filter to check who created or revised the Podio Item that triggers the flow.
For example: If you want to set restrictions on who can make edits on an Item, you can add this filter.
Select the flow Trigger and add this Creator/Editor filter.
This flow will now be triggered every time the Current Revision User is equal to "Rene Prost".
Complete flow by adding Actions to complete your workflow steps.