1 Better exposed Filters for 2 views blocks
You want to create an attachment view display and add it to your main display. For example, if you currently have the OpenMaps display working, create a listing display as an attachment and attach it to the OpenMaps display. Make sure you set "Inherit exposed filters" to "yes" to ensure both displays are using the same set of filters.
In views 3 you can find this settings in the Attachment display settings: