In the top toolbar of the segment, click on Purchasing > Rentals to open the purchasing overview for rental items. Alternatively, open the overview from the Home tab by clicking on Purchasing > Rentals, if necessary with company details and a time period.
In the list of orders in the centre of the page, filter for Inventory items and select the correct item group in the list of item groups on the right.
In the list of suppliers at the bottom right, click on the Supplier you want to place an order. The list of items displayed will then only show those items that the selected supplier has in their range.
Click on Confirm values to adopt the required quantities as order quantities.