I managed to do this today:
After publishing the InfoPath form to a new SharePoint library go into the SharePoint Form Library list settings. Add two new columns for each Person Picker you want to filter on using the [Me] function.
AccountableAccountID (Single Line Of Text)
Accountable (Person or Group)
So you've added these via SharePoint and not InfoPath and promoted them.
Then re-publish your InfoPath form but in the Property promotion select the AccountID field and set the column name to AccountableAccountID (this should be in the list of options and is the field you created above via SharePoint)
Once this is done you will need to create a Workflow using SP Designer
Make the Workflow run on every save/update of the item.
The workflow will have one action - Set Filed In Current Item
Set Accountable to Current Item: AccountableAccountID
When you save a form it will run this workflow, which will lookup the AccountableAccountID (e.g. domain\user.name) in you user directory/AD and set the Accountable (Person or Group) field you created to the user.
You can then use the Accountable field in a list filter using the [Me] function.