Yes you can create a sub account of inventory asset in the chart of accounts, as well as creating additional top level inventory asset accounts
BUT
but what you are wanting to do is not going to work in QB.
QB works on names, every transaction is isolated by name in the background, so there is really no usable reason to create sub accounts at all. Think of a name as a sub account.
And if you do have additional inventory asset accounts, QB lumps them all together in an inventory valuation report, that may or may not cause an issue depending on what you are trying to get done.
If you would explain the full detail behind your wishes, we can probably help to find a way to get it done.