Updating State and Country Picklist

You can use the Metadata API to edit existing states, countries, and territories in state and country/territory picklists. You can’t use the Metadata API to create or delete new states, countries, or territories. Refer
Once you have loaded State and Country Picklist you can update them, like selectively activating a country as per your use case.
Options described here explains how to activate a particular country or countries.

Topics

Option-1 Activating using Recorder application
Option-2 Using ONNU Chrome Extension
Option-3 Using CLI mdapi
Option-4 retrieve into SFDX project using source:retrieve

Option-1 Activating using Recorder application

Before

before

Replying the recording

Activating recording

After

Option-2 Using ONNU Chrome Extension

SCPL Update ONNU

Option-3 Using CLI mdapi

Retrieve

sfdx force:mdapi:retrieve -k unpackaged/package.xml -u mohan.chinnappan.n.sel@gmail.com -r .

Retrieving v56.0 metadata from mohan.chinnappan.n.sel@gmail.com using the v57.0 SOAP API
Retrieve ID: 09S4x00000F0DGMEA3
Retrieving metadata from mohan.chinnappan.n.sel@gmail.com... done
Wrote retrieve zip to /Users/mchinnappan/Downloads/updates/unpackaged.zip

jar tvf unpackaged.zip 
569563 Mon Mar 27 23:41:02 EDT 2023 unpackaged/settings/Address.settings
   226 Mon Mar 27 23:41:02 EDT 2023 unpackaged/package.xml

Edit Address.settings as in the Option-2 (ONNU option) to update active tags to make updatedSCPL.zip zip file

Deploy the edited Address.settings file

sfdx force:mdapi:deploy -u mohan.chinnappan.n.sel@gmail.com  -f updatedSCPL.zip  -c --verbose --loglevel TRACE -w 1000

Deploying metadata to mohan.chinnappan.n.sel@gmail.com using the v57.0 SOAP API
Deploy ID: 0Af4x00000YsXnoCAF
DEPLOY PROGRESS | ████████████████████████████████████████ | 1/1 Components

=== Deployed Source

 Type            File                                 Name        Id 
 ─────────────── ──────────────────────────────────── ─────────── ── 
                 unpackaged/package.xml               package.xml    
 AddressSettings unpackaged/settings/Address.settings Address

Option-4 retrieve into SFDX project using source:retrieve

cat package.xml

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
   <types>
       <members>Address</members>
       <name>Settings</name>
   </types>
   <version>56.0</version>
</Package>

sfdx force:source:retrieve   -u mohan.chinnappan.n.sel@gmail.com -x  package.xml

Retrieving v56.0 metadata from mohan.chinnappan.n.sel@gmail.com using the v57.0 SOAP API
Preparing retrieve request... done
=== Retrieved Source

 FULL NAME TYPE     PROJECT PATH                                              
 ───────── ──────── ───────────────────────────────────────────────────────── 
 Address   Settings force-app/main/default/settings/Address.settings-meta.xml

Now you can commit this into your version control and make changes to the Address.settings-meta.xml in your editor

vi force-app/main/default/settings/Address.settings-meta.xml

Deploy the updated Address.settings-meta.xml into the org

sfdx force:source:deploy   -u mohan.chinnappan.n.sel@gmail.com -x package.xml

Deploying v56.0 metadata to mohan.chinnappan.n.sel@gmail.com using the v57.0 SOAP API
Deploy ID: 0Af4x00000YsZyUCAV
DEPLOY PROGRESS | ████████████████████████████████████████ | 1/1 Components

=== Deployed Source

 FULL NAME TYPE     PROJECT PATH                                              
 ───────── ──────── ───────────────────────────────────────────────────────── 
 Address   Settings force-app/main/default/settings/Address.settings-meta.xml 
Deploy Succeeded.

Salesforce Development Notes