Select Lookup icon by the item code

Click filter button

Add product line as the filter element, then set the operand and product line code

Click the check box to retain the filter

The filter button will display in red font when the filter is active.

Click filter again, reset to clear the filter when done.

You can set your filter and then use the Zoom (ALT+Z) button in the upper right, this will launch a new Item Inquiry/Maintenance task for the selected item and leave your list alone so you don't have to repeatedly pull the list up.

I think someone once had an example of using a button script to assign a browse filter or created custom navigation buttons for browsing by a specific criteria but this requires Custom Office and scripting knowledge.

I think these are the threads I was thinking of.

Customized Next Button On Invoice Inquiry - Sage 100 Personalization, Customization, and Productivity Tools - Sage 100 - Sage City Community

Record Filtering When Using Next / Prior Buttons - Sage 100 Personalization, Customization, and Productivity Tools - Sage 100 - Sage City Community

Thank you for your help.  That will help.