In a microflow do a retrieve on the object with a sort on the date (or last changed or created depending on what you want). Then with the list head action you get the first object of that list. See documentation here: https://docs.mendix.com/refguide/list-operation
When retrieving data in a microflow you can use retrieve actions and pass an XPath, order and limits.
If you want to retrieve the latest record using a microflow. Simply add a retrieve action and select the option first.
Then in your sort order select the date attribute and select descending. This will then get you the last record that has been added.
If you want to change the order on your datagrid, you can select an option for the sorting. So that you can sort by descending date.