Hi, Carolina,
as far as I understand you want to have a button inside your survey.
Clicking opens a second survey while the first one stays.
The easiest way is just to insert a link like
Code:
<a href="path to second survey" target="_blank">Click for second survey</a>
.
To ease everything there is a button in the question editor to insert a link.
You can insert it either in question text or in answer options.
Of course yo can style this by some more HTML and css.
I would create a button like <input type="button" ... or so.
Best regards
Joffm