trigger deployments based on release flagged approved

Our continuous deployment workflow uses release flags (approved, broken) to determine if a release should be promoted to next deployment phase.
For example if a release is flagged as approved by QA leader then this will trigger a deployment to staging deployment environment.

Currently we can only trigger deployments based on schedule and successful builds. See https://confluence.atlassian.com/display/BAMBOO/Triggers+for+deployment+environments

We would like to be able to trigger deployments to specific environment based on release approval flag.