To share this venue with other organizations you can either:
1.) On the list view of the Organization Venues, click the number under "Organizations."
2.) Click into the Organization Venue you want to add a pitch to and click the "Access" tab at the top of your screen.
Both of these options will bring you to the screen below where you can begin to type the organization's name in before selecting their name from the drop-down. Click "Share Venue" to then grant this organization access to this venue.