I want to alter entity auto complete results in hook\_form\_alter.
My functionality is

> 
> 1) I have a entity reference of taxonomy and bundle is tags which is
>  Level 2 (Field Name: Product Child) 
> 
> 
> 2) In this I select one term from Level2
> 
> 
> 3) I have another entity autocomplete which refers to taxonomy
>  tags Level 1 (Field Name: Product Parent)
> 
> 
> 

Now my question is if i select one Level 2 Term in Product Child Field , is there any option to show only parent terms of that Product child field in Product Parent Field
Like :

```
Cabbage (L1)
 -> Fruit (L2)
 -> Flower (L2)

Lemon(L1)
 -> Lemon Fruit(L2)
 -> Eatable (L2)

```

If I select Fruit in **Product Child** field I want to show only Lemon in **Product Parent** Field. Is there any way to do this.