Find which Flows use a specific action or subflow

Action instances are stored here:

instanceName.service-now.com/sys_hub_action_instance_list.do?sysparm_query=&sysparm_view=

Subflow instances are stored here:

instanceName.service-now.com/sys_hub_sub_flow_instance_list.do?sysparm_query=&sysparm_view=