JIRA Cloud - How can I show/hide a field based on value selected in another field.
Not really, you could look towards some other apps but on Cloud it's hard/not possible to interact with screen fields like we would want to.
I'd suggest to check out proforma and see if that fits your needs as it should become availalable really soon.
Recommended Learning For You
Level up your skills with Atlassian learning
Learning Path
Become an effective Jira admin
Manage global settings and shared configurations called schemes to achieve goals more quickly.
Streamline Jira administration with effective governance
Improve how you administer and maintain Jira and minimize clutter for users and administrators.
Learning Path
Become an effective Jira software project admin
Set up software projects and configure tools and agile boards to meet your team's needs.