Multiple Prices based on User in Craft Commerce
User groups are not a FieldType so you can create a category that matches the title of the userGroup or put the actual category as a field on the User and the Variant. Then in your template do something like this:

{% set userGroup = currentUser.userGroup.first() %}

{% set variants = craft.commerce.variants.product(product).relatedTo(userGroup) %}

This would probably be the best way since you aren't reliant on string matching a title to find the correct variants.