Since Item and Line ID are not available from an Opportunity Search, we can use a Transaction Search instead.
1. Navigate to Lists > Search > Saved Searches > New.
2. Select Type = Transaction
3. From the Criteria tab, select Type is Opportunity.
4. Under Results tab > Add Item and Line ID
Note: For example you have 4 line items, the first line item is equivalent to Line ID=1, 2nd line item is Line ID=2, 3rd item is Line ID=3 and 4th item is Line ID=4.