I am using Sharepoint 2013. I have an "A" list with a lot of data in 2 column. Column "A1" is the name of the item and "A2" is the ID of the item. In the list "B" there are a lot of columns and the user can create new items. I would like to make the user able to have 2 text (or maybe dropdown) field. If the user starts to write in the "Field1" a list appear and the user can select an element from the "A1" column. If the user selected it, the "Field2" automaticaly filled with the same item's ID from the "A2" column. Or the user can do the same with the "Field2" so if the user choose the ID, the name of the item appears in the "Field1".
In short I would like to add two element by selecting one, but the user is free to choose to use the name or the ID of the item.
Any userfriendly method what result the same is good for me.
Thank you very much for any suggestion!