Discount Volume, or more commonly known as Volume Pricing is more of a data structure than it is a UI element. 

Before Volume Pricing can be used it must be set up in price groups/marketing: https://docs.miva.com/miva10/reference-guide/price-groups-volume-pricing

The discount volume page code takes a product id assigned to some l.settings variable, such as:

<mvt:assign name="l.settings:vol_prod_id" value="l.settings:product:id" />
<mvt:item name="discount_volume" param="vol_prod_id" />

After the "discount_volume" call you get an array of values that can be used for whatever. 

The discount volume template can be blank, these values show up after the page item.

Example:

l.settings:discount_volume:table: 

[1]:formatted_price = $25.00
[1]:high = 23
[1]:low = 1
[1]:price = 25

[2]:formatted_price = $20.00
[2]:high = 47
[2]:low = 24
[2]:price = 20

[3]:formatted_price = $15.00
[3]:high = 71
[3]:low = 48
[3]:price = 15

[4]:formatted_price = $10.00
[4]:high = 0
[4]:low = 72
[4]:price = 10