Currently you can do a filter on a column name of Stock.StockName where Rhubarb will (if supported by the repository type) perform a join query to tblStock and actually filter on StockName. However we should be able to support Stock.Category.CategoryName and in fact any number of 1-1 joins.
This work was already looked at in Core on a branch that wasn't merged so could possibly be recovered.
Currently you can do a filter on a column name of Stock.StockName where Rhubarb will (if supported by the repository type) perform a join query to tblStock and actually filter on StockName. However we should be able to support Stock.Category.CategoryName and in fact any number of 1-1 joins.
This work was already looked at in Core on a branch that wasn't merged so could possibly be recovered.