Note: This answer was created with the help of an AI tool.

You seem to be attempting to prioritize the locations of partially used commodities in your Bill of commodities (BoM) in order to streamline inventory consumption. Although location priority inside a single BoM is not natively supported by Acumatica's regular BoM functionality, there are a few possible workarounds and solutions you might want to look into:

1. Location-Specific Warehousing: Acumatica does allow for multi-location warehousing, but location prioritization within a BoM isn't inherently available. You could create separate warehouse locations in your system for the "partial bags" and "new stock" and manually manage this via inventory transfers or planning processes. This way, you can set a default location for production orders, and your staff can manually adjust to secondary locations when needed.

2. Manual Overrides in Production Orders: You can set up your Production Order to pull materials from specific locations, but it requires manual intervention. When creating the Production Order, you could instruct the system to use the partial stock first by manually specifying the location of the "partial bag" and then pulling the rest from the standard location.

3. Customization: If this is a consistent need, you might consider a customization or a modification to the Production Order logic. A developer could create a routine that automatically prioritizes inventory from a certain location first (i.e., the "partial bag" area) and generates a report that would reflect where materials need to be pulled from.

4. Business Events/Notifications: You can set up Business Events to alert employees when they need to pull from multiple locations. This won't affect the BoM directly, but it would guide your employees on the production floor to pull the right quantities from different locations.

5. Splitting Production Orders: Another workaround could be creating two production orders or split lines on the BoM that tell employees to use up "partial" bags and then proceed to new stock. Though not fully automated, it gives better visibility and control over material usage.

While none of these options will offer a genuine "hierarchical" pull from two locations directly in the BoM, they can assist in more controlled process management, particularly with some innovative setups or little adjustments.

Depending on how many locations you want to prioritize, you might be able to handle this. For example, if you just want to prioritize the partial storage location first and then use the regular FEFO/FIFO lot issue method then this would work. You would simply set the Warehouse and Location on the BOM line which would tell the production order to look for material in that location first. 

The problem is there is no “secondary” location. After this default location Acumatica will then use the issue method and suggest the next available lot.

I show an example in this thread: