You are correct. There are three linear timelines: Yennefer's, Geralt's, and Ciri's, which start at different times but all coincide by the final two episodes.
Here is a timeline of the events depicted in the show:
Dates and relative position of events are taken from 3 sources:
Ep.1 Ciri: You won your first battle at Hochebuz when you ...
Each episode of the first season of the show covers different stories from the first books by Andrzej Sapkowski.
Episode 1 - The End's Beginning is based on the 4th story from the book The Last Wish, called The Lesser Evil.
Episode 6 - Rare Species is based on the first story from the book Sword of Destiny, called The Bounds of Reason.