What type of light switch is this called?

Hi everyone

I'm trying to find a light switch that has a second toggle, a tiny horizontal one thats directly under the main light switch. I cannot put in the right combination of terms to find it.

Ultimately my goal is to rewire the bathroom switch. Right now the light and fan turn on together. I want the bottom small switch to be an on/off for the fan that then ties into the switch for the light, so you can decide if the fan is on or off when you hit the light switch.

Plz halp.

Edit:

[Example sketch](https://postimg.cc/nsS8zjd4)