Can you help me with an Infopath repeating section and filtering of fields?

I have to create an InfoPath form. I have 2 lists in my SharePoint Online,

1. list Activities list all activities.
2. List Hazzard list all hazzards, per activity. (one activity = many hazzards)

So in InfoPath, I create a drop-down list that shows activities, once the necessary activity has been selected a repetitive table list all Hazards for that Activity. (upon selection of activity, I query the hazard table to list all hazards linked to that activity selected)

But this form needs to enable the user to select unlimited activities and each activity’s hazard should be listed. So the above needs to be in a repetitive section. But when I repeat the section and insert another activity in next section, it refreshes all activities and hazards in all sections with the one selected. See problem underneath: Activity 1 must remain on ‘Compacting & Filing’ and Activity 2 must filter newly selected activity Hazards.

How can I ‘fix’ what was selected in first Activity 1 and then select a new activity in Activity 2?