Hello Frias
Welcome to the SBB Community. We do answer questions in either German, French, Italian, or English.
If you want to travel in all three countries there is the Eurail or Interrail Pass.
https://www.eurail.com/en
If you want to travel in the Basel area, with border crossings, there are Triregio tickets available.
https://sbb-tickets.cc/en/tickets-offers/travelcards/point-to-point-regional-travelcard/fare-networks/triregio-travel-without-limits.html
Alternatively, there are international point-to-point tickets; these are recommended if you travel only once between each country.
For a better advice we would have to know your itinerary.
Kind regards,
Roland