Jira can't restrict view or edit field value at field level, although it can restrict at issue level.
With this app, each custom field can hide value or be read-only based on permission to get security and privacy.

Secure Custom Fields - Security & Permission - for Jira

AtlassianMarketplaceApi

Ricksoft provides add-ons for Atlassian Jira and Confluence to help customers manage their projects. With WBS Gantt-Chart for Jira being our flagship product, our apps are trusted by more than 5400 innovation leaders across the globe. We are proud to be a Platinum Marketplace Partner and a Platinum Solution Partner.