You would need to:
- Create a NPE to save the objects from the autocompletes (by association)
- Have a microflow as source in the data grid 2
- This microflow will return a list. Like, do a retrieve of your list then use list operation > filter to filter the list with the objects that the user selected in the autocompletes
- Add an event on change to all autocompletes, this microflow should refresh the NPE object.
Yet, to save the trouble of bugs, low performance and time consuming on developing, I would recommend you to use the Text Filter from data grid 2.