Workbasket belongs to "Data-Admin-Workbasket" class. I have reviewed the class and all the OOTB properties.
It's mapped to "PSALLDATA.pr_data_admin" table in the PegaData. You could try running a select query from the backend to retrieve all the columns and look for the column if there is any relevant column which could serve the purpose.
Luckily, I was just reviewing an article and hope it could be helpful in your case.
Rule references are created when one rule refer other in a model-driven way (Property-Set etc. ). They are stored in each rule.
Usually, if you open XML for any rule like data page, it has a "pxRuleReferences" page and it contains all the rules that this data page refers. Similarly, other rules which use this data page will have an entry in their pxRuleReferences.
Note: Using or calling rules directly in java steps will not make an entry in pxRuleReferences and hence will not come in View References window.
Though, I tried to view the XML of workbasket rule and couldn't find an entry for this. Just try to retrieve the information regarding pxRuleReferences from the backend.
The workbasket can be referenced in the flow rule in assignment shape for routing. The work basket can be referenced in an activity as well. It can also be referenced in operator profile. The question is to list all the rules or data instances where a particular work basket has been referenced.