"What would you like to get?"
Translation:Co byś chciał dostać?
The inflected particle "bym/byś/by/byśmy/byście" is a special type of sufix, which is movable. This particle may attach to some words and is written separated from others words - rules of that are long, but for most occasions it is enough to know, that it is attached to verb if placed after the verb, and separated if written before the verb.
What you wrote is slightly incorrect, because the form "chciała" is 3-rd person singular feminine, while the particle "byście" 3-rd person plural (for all genders the same). Hence, the correct forms would be either "chciałabyś" (3p sing. f.) or "chciałybyście" (3p pl. f.).