Before publishing the application, you can create bookmark of the default filters you want to apply. Follow below steps.
1. Make the selections in the field/s which you want to use as default filters.
2. Create a bookmark.
3. Save the application and publish it on Qlik sense server.
This bookmark will be available to all users. Any user who will have the access to the application will be able to apply that bookmark in the published app and this way default filters will be applied.
Hope this helps.