one item contains related items

Dear All

i have the following case,

one of the provider send items as the below details

Item X - Major one

        Item y --- Sub

        Item Z--- Sub

is there any possibility to link items together and i will use and work with only item X,

for example, i will create PO for all items, but i will receive Item X only(sub items received automatically) , and i will issue item X only (sub items issued automatically)

BR