To create a Location Group based on your HighLevel SaaS Configurator plans, click the "Add SaaS Config" button.
You should now see a new row of fields with the yellow "SaaS" badge.
You'll need to find the Price ID for the specific SaaS Configurator plan in your HighLevel. (Not the 'Plan ID'.)
Enter the Price ID(s) you want to connect to this Location Group.
You can use both monthly and annual/yearly Price ID's if you need to, or just use one or the other.
Click the blue "Save" button when you are done configuring your Location Group.
Now any new sub account attached to a SaaS Price ID you've entered here will adopt any Location Group customizations you set up.