In the past 20 years, Swiss have undergone dramatic changes in the Swiss citizenship laws. A Swiss woman will no longer lose her citizenship for marrying a foreigner. Swiss do not offer child citizenship for children being born on the Swiss soil. A person will be a Swiss candidate if he or she is the child of married parent at least one of whom is from Switzerland.
Swiss allow citizens to have multiple nationalities, so if a naturalized person loses their citizenship totally depends upon the other country in question.
Through birth, naturalization or naturalization, Swiss citizenship can be acquired. The fact sheet given here set out the procedures and requirements for Swiss nationals willing to apply for Swiss citizenship for their foreign spouse or children. https://www.eda.admin.ch/content/dam/countries/eda-all/en/Einbuergerung-Kinder-2014_en.pdf https://www.eda.admin.ch/content/dam/countries/eda-all/en/Einbuergerung-Frauen-2014_en.pdf
You might also get additionally details on the official SEM website.
Applicants living abroad will have to submit their naturalization or naturalization forms to the Swiss representation that includes their of residence. The final decision will be taken by the State Secretariat for Migration submitted for approval by candidates living abroad. If you are eligible to apply for naturalization or naturalization, contact the Swiss representation that includes your place of residence to acquire the needed documentation.