Relationship among four model

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1

I have four models like below:

Sale (id)
SaleEntity (id, sale_id, sku)
Item (id, sku)
ItemEntity (id, item_id, quantity)
I have hasMany relationship in Sale table for SaleEntity table and I need relationship between SaleEntity table and Item Table on sku basis as well.

Result should be like below format.

Array
(
[Sale] => Array
    (
        [id] => r16148516            
    )

[SaleEntity] => Array
    (
        [0] => Array
            (
                [id] => 22
                [sale_id] => r16148516
                [sku] => abc                 
            )
        [1] =>  Array
        (
            [id]    =>  23
            [sale_id]   =>  r16148516
            [sku] => xya 
        )

    )
[Item]  =>  Array
    (
        [0] =>  Array
            (
                [id]    =>  5
                [sku]   =>  abc
            )
        [1] =>  Array
            (
                [id]    =>  6
                [sku]   =>  xyz
            )
    )

[ItemEntity]    =>  Array
    (
        [0] =>  Array
            (
                [item_id]   =>  5
                [quantity]  =>  200
            )
        [1] =>  Array
            (
                [item_id]   =>  6
                [quantity]  =>  100
            )
    )

)