Intercompany Company transfer issue

While doing intercomppany transfer from A to B ,  in sales order ,line item gets auto split based on packaging critria. eg. say SO is for 150 qty of item ZZ. As we can pack max 30 per box , the item lines is getting auto split ( 30+30+30+30+20) in sales order accordingly.

I would like to know where exactly this functionality is defined .

When receiving is done at org B, it again comes as multiple split lines instead of a single line meaning we need to do receiving for every single line individualy.

Again would like to know where and how  this is configured as would like to chnage it to one line .