Price discrimination isn’t a subcategory of dynamic pricing. Dynamic pricing is equivalent to what is colloquially referred to as surge pricing, whereas price discrimination is based on the buyer’s perceived willingness and ability to pay.
Dynamic pricing could technically fall into the category of price discrimination if the discrimination is temporal (e.g. people who need a taxi at 8:00 AM pay more than people who need a taxi at 8:00 PM), but generally price discrimination refers to changes in price based upon anticipated demand, whereas dynamic pricing refers to changes in price based on actual demand.
Dynamic pricing could technically fall into the category of price discrimination if the discrimination is temporal (e.g. people who need a taxi at 8:00 AM pay more than people who need a taxi at 8:00 PM), but generally price discrimination refers to changes in price based upon anticipated demand, whereas dynamic pricing refers to changes in price based on actual demand.