You can't do an OR with the built in filtering function. Not sure why this has never been implemented but there we are.
If its a filter you don't need to change, you can workaround by using a (hidden) calculation field then filter on the calculated field.
@created on is available in calculation field but Last Updated is not.
So you'd have to create two (hidden) fields on your app that are updated by Globiflow
Last Updated - update whenever the item changes
Current Date field - Update every night
Then your filter calculation field would be something like
moment(@Current Date).diff(moment(@Created On), 'days')<=7
moment(@Current Date).diff(moment(@Last Updated Date),'days')<=7