The current method for finding a certain stock record by serial number, or batch number (or any other POP custom field), is pretty convoluted and confusing.. so much so that some clients were resorting to exporting historical stock reports to try and track down certain serial numbers.
The way to do it currently is that you have to go to the Products Page, then search by text, then click into the product that comes up in the results, then navigate to a different tab called "filtered report". The discoverability of this process is very low, you would need to be shown these steps by someone to know that they exist.
"Search for Anything" is the most likely place that they will go with a particular serial - it would be very powerful if this was capable of finding these stock records and directing them straight to them.
However, if this is impossible, a new page called "Stock lookup" could also suffice. Just something that's obvious... and maybe search for anything could direct them to use this tool if it can't find any results itself.