Hi,
for each field you can choose condition based on its value.

see screenshots about our "You Job" configuration.
Basically it have 3 options:

1|Web Designer

2|Developer

3|Other

And 3 conditions:
- If equal to custom value "1" (web designer) show field "Know how to use photoshop" (Inverse:yes, mean that otherwise hide field)
- if equal to custom value "2" (developer) show field "Known languages" (Inverse:yes, mean that otherwise hide field)
- if equal to custom value "3" (other) show field "What do you do" (Inverse:yes, mean that otherwise hide field)