The options object that is passed to the showIf function is a map of the current options set on the component. Hopefully you are able to accomplish what you need with that. If that does not work and you need access to the parent of the current component, the update we have planned to fix this issue for you: Get parent block in Builder.registerComponent - #6 by korey will also fix this!
hideFromUI and showIf provide similar functionality, so you can essentially use either one interchangeably. If you never want a field to be shown (i.e. you are using the field to add data to the component from your codebase and do not want someone to be able to edit it in the Builder editor), hideFromUI is simpler to use. showIf is more helpful if you want to dynamically hide or show an input to a user depending on other settings.
Important note: showIf won’t work inside List’s subFields array. But we got this “hack” to make it work (TS type doesn’t support strings for that fields, so we have to ignore ts…)
//@ts-ignore example provided by Builder to convert value to string in subfields
showIf: `options.get('someField') === 'someValue'`,