Connect Magento customer groups with price lists from your ERP. This imports advanced (tier) prices per customer group, for all websites.
Each row connects:
a Magento Customer Group, and
a price list from your ERP.
Good to know
To set prices per customer group on a specific website, use Website/Customer Group - Pricelist map. It needs Magento Catalog Price Scope set to Website.
If the list is empty, check that Magento is connected. An empty list almost always means the connection, not the setting.