Top 5 bank in Switzerland?

Answer 1

The first two are easy to mention:
1. UBS
2. Credit Suisse

Then it depends a bit on the criteria - as far as I know the No. 3 would be the Zurich Cantonal Bank (owned by the Swiss Canton of Zurich). A "Canton" is the province (26 altogether in Switzerland).

4. Banque Cantonale Vaudoise - Waadt Cantonal Bank
5. Migrosbank

==> the Raiffeisen Group actually would be No. 3, but the different banks are independent units, there is no holding, only a fairly loose cooperation.