Assigning Line card suppliers for a Single/Multiple is quite similar to the usual assignment you carry out. 

Referring to the Assignment of single MPN and Assignment of Multiple MPNs would give you more clarity on this.

If you want to source a component with part no. #GRM188R71H104KA93D CAP-001, from Murata Electronics, then use the 'Line Card' option to see all the Line card suppliers for that MPN.

To assign for a single MPN follow the steps below-

Step 1:  Go to the RFQ section of the dashboard and select the RFQ you wish to find Line Card suppliers for.

Step 2: Click on the search icon and a window with a list of all the suppliers pops-up.

Step 3: Click on the Line Card button at the top.

Step 4: You get a list of all the line card suppliers for selected MPN.

Step 5: Here you can select the suppliers and click on the 'Assign' button.

Suppliers are assigned for the selected MPN and you can find the list by clicking on the Assignment card.

To assign Line Card suppliers for multiple MPNs follow the steps below-

Step 1:  Go to the RFQ section of the dashboard and select the RFQ you wish to find Line Card suppliers for.

Step 2: Check the checkbox beside the Web Offer button and further click the Bulk Assignment button. In the pop-up window you get two options- By Supplier & By Line Card.

You can select suppliers and then just check the checkbox that says- Matches Line card. This gives you a list of Line Card suppliers for the selected MPNs.

Step 3: Check the 'By Line Card' option. A list of Line Card suppliers for all the MPNs is displayed.

Step 4: Select the suppliers of your choice and click on the 'Add as Assignment' button at the bottom of the list.

 
You can check all the suppliers in the Assignment card.