crm_core-8.x-3.x-dev/modules/crm_core_activity/crm_core_activity.links.menu.yml

entity.crm_core_activity.collection:
  title: 'CRM Activities'
  description: 'Manage CRM Activities.'
  route_name: entity.crm_core_activity.collection
  parent: crm_core.overview

entity.crm_core_activity_type.collection:
  title: 'CRM Activity Types'
  description: 'Manage CRM Activity Types.'
  route_name: entity.crm_core_activity_type.collection
  parent: crm_core.manage