Specific fields appear in New Request depending on answers to prior fields

As an admin managing WorkOrder forms and approval paths, I would like to request that if an end user follows a specific pathway, then they will be led to a special WorkOrder submission format that contains a unique field with a drop down menu of Inventory items that ONLY appears if a specific Problem Type and Purpose are selected. I'm imagining multiple branching pathways of "If this Purpose tyle"... "Then this Problem type".

For example, I'm trying to create new text fields that will appear if an end user follows the following pathway: New Request = Technology, -> Purpose = Hardware -> Problem Type = Toner Request = (a new field named "Printer Model")....but I only want this visible if the user selects Toner Request.