Maybe you can move the desired group (Right click on group >> show only Associated Entities) to a new part (select the entities in UI and right click on part >> move here) and export that part or parts or assembly can better be retrieved and exported using Apex scripting capability.
Maybe you can move the desired group (Right click on group >> show only Associated Entities) to a new part (select the entities in UI and right click on part >> move here) and export that part or parts or assembly can better be retrieved and exported using Apex scripting capability.