This should be possible with actions, you need to set an action from the Position History table so that when a new record is created it copies the value from the relevant fields in that table into the relevant fields in the parent record. Maybe if you can upload a screenshot of the action that's not working I can see if that's been set up incorrectly.
You could also try to use a Pipeline, but as long as you don't already have 10 actions connected to that table, they should work. Make sure the action is enabled as well, when you see the list of actions for a table, make sure it has a green tick next to it.
