A good way to explicitly and dynamically control which inventory hosts or groups a playbook executes against is by defining the host’s field in the playbook as a variable, commonly named “target”.

---
- name: Upgrade software.
  hosts: "{{ target }}"
  roles:
    - jiholland.cisco.software

This variable is then defined as an extra vars each time you run the playbook, and if you forget it the playbook will fail immediately as hosts are a required playbook attribute.

$ ansible-playbook software_playbook.yml -e "target=switch1,switch2"

In this example, the playbook is executed on switch1 and switch2 from your inventory.