Escort services in Seville or Sevilla as the Spanish say are a bit of a neutral occupation. Poverty isn’t a huge issue here; so young women aren’t forced into prostitution. The ones that do work as escorts in Seville do it because they chose to, not out of necessity. Illegal immigrants and human traffic are a different story but I trust we’re not looking into that kind of market. Immigrants make up over 90% of Spanish sex workers. That number alone pushes the government into legalization talks, for the sake of the women. When it comes to current legalities, prostitution is ignored and unregulated. It’s not considered a job, so you can “run” a brothel, but you can’t “hire” any girls. Pimping is criminalized, but Seville escorts are allowed to do their own thing.
Escorts in Seville are usually available for online bookings. Everything revolves around escort agencies in Seville. Amigas de Silvia (https://www.amigasdesilvia.com/), Luxury Private (https://www.mluxuryprivate.com/) and Lujo por Sevilla (https://lujoporsevilla.com/), just to name a few. As often is the case in Spain many girls working in the erotic industry have their roots in Latin America; especially Brazil, Colombia and Venezuela are well represented. Your choice of escort directories in Seville is limited to H Escort (https://www.hescort.com/) and Eros Guia (https://www.erosguia.com/), which are both pretty good. Pasion (https://www.pasion.com/) is a great site with classifieds, that is to say: if you can get past the language barrier. Bear in mind that on Spanish escort sites the ladies are often labelled as prostitutas or putas. Sevilla escorts in don't charge the top prize: expect to pay something between €150 and €200 for an hour.
There used to be a red light district in Seville around the Alameda de Hercules. It went all family-friendly and streetwalkers had to spread around other parts of the city. You could say that working girls and brothels are sort of centralized around the train station or within a 500m-1km radius around it. Don’t count on anything officially advertising as a brothel. A quickie in a dark alley will cost around €50. Action with a Romanian immigrant in a filthy brothel shouldn't set you back more than €100. That is, if that's your cup of tea.