You're on the right track. Yes, there are two things you can do:
1. Manually copy-paste the appropriate YAML files (or portions of files) from the application module to the development module. (Shutdown your local process first, and restart after you've moved things around.) The default auto-export config will update any JCR nodes that already exist in the development module in-place, while any new nodes will go to the application module. This is a good first step.
2. If you plan to build up a bunch of sample data over a period of time, you can adjust the auto-export config to direct everything under a specific JCR path to the development module automatically. You can do this for more than one JCR path, for example to handle sample documents and sample assets. It's helpful to group your sample content into a folder, so you don't need to list individual document nodes.
To do this, you'd typically adjust the YAML in repository-data/development/src/main/resources/hcm-config/main.yaml. That file includes a definition for the JCR node /hippo:configuration/hippo:modules/autoexport/hippo:moduleconfig. It adds a new value to the property autoexport:modules to register the 'repository-data/development' module. If you change that value to e.g. 'repository-data/development:/content/documents/myhippoproject/samples', all the new content under that JCR path will go to the development module automatically. You can also add the same module with more than one path, like so:
value: ['repository-data/development:/content/documents/myhippoproject/samples',
'repository-data/development:/content/gallery/myhippoproject/samples']
The full docs for configuration options are available here:
There are some advanced use cases related to config vs content categories, but you shouldn't worry about that unless you have a specific problem with how things get exported.