There isn’t a way to see the database changes while a microflow is still running, because database changes are committed after the called microflow, including any sub-microflows, is finished. This is a good thing, because it improves performance of your application by limiting the number of database connections.
You can add logging (Log message action) to your microflow or add breakpoints (right-click on action – Add breakpoint) to observe what is going on in detail. Or if you can explain a bit more about your situation and what you want to check, we can help you to find another solution.
In the community commens there is a End Transaction java action. This send changes made to the database while the microflows still runs.
This is indeed a performance killer so use with care.
In Community Commons module there is also a commitInSeparateDatabaseTransaction Java action which commits an object directly into the database at the point of execution, so the changes to an object would be visible even if the microflow would not end.