In Salesforce, you can exclude a user from Multi-Factor Authentication by assigning a permission set that gives such user the Waive Multi-Factor Authentication for Exempt Users permission.
​
This permission allows you to exclude a user from MFA without modifying the org-wide MFA settings.
​
In this Salesforce org (screenshot below), the permission is named 'WMFA' and found under Setup > Users > Permissions Sets.

In order to deploy this permission from your org, you'll need to include Permission Set metadata type in your metadata filter.
​If it's an entirely new permission set created in the source org, you'd find it under the Permission Set metadata type in your comparison results.​
​

You also want to include for deployment the component found under Permission set: Set of user permission for a new permission set (as shown on screenshot above), as it will deploy the enabled checkbox for Waive Multi-Factor Authentication for Exempt Users permission.
​

If you're only deploying the Waive Multi-Factor Authentication for Exempt Users permission from source to target (as opposed to the entire permission set), it's likely you'd find it in your comparison results under Permission set: user permission metadata type, and it would look like this:
​

The deployed permission set can be found in the target org under: Setup > Users > Permission Sets > permission named 'WMFA' with the description 'Waive Multi-Factor Authentication for Exempt Users' > System Permissions (in 'Systems' section).