Show xProperties from one item type to another item type

Hi Team

I need a help to implement one logic. I have xClass configured in Document Item type and Part has document number field. On Select of document number, I want to show the related xClass properties of document in Part. How to achieve this.

Example : 

Document1 has xClass Group1 with 3 properties

When user select Document1 in Part Itemtype, Part should show the Document XClass in Part relationship

Thanks