Stick Conditional Field Record For Free

Edit the Lightning page layout by clicking on the Setup gear in the upper-right-hand corner, and select Edit Page. Add the conditions to the related record lightning component. Click on the component, then select Add Filter to input filter criteria. Select save.

From the Case Record Page, click any component that you don't want the agent user to see, and then proceed to the component attributes menu. For example, you can select Feed and then configure its settings. From the Set Component Visibility dropdown, click + Add Filter. Set the filter with these configurations.

You can do this by assigning a different record type with a workflow. This record type would have a separate pagelayout with the fields you require to be read only set as such. You may have to explore VisualForce pages. You can embed one in the Opportunity layout and have it act upon your fields.

Conditional Visibility allows you to specify when you want a particular page component to be visible. We can use this to customise our pages to make information appear when it is relevant to the business process, and be hidden when not, so that we can keep the page as simple and concise for our users as possible.

You might want to use conditional field visibility in Salesforce so you can decide which fields you would like to view or hide on a specific record page.

For the screen component, expand the Set Component Visibility section. Define the conditions for when the component is visible. Define the filter logic if you entered multiple conditions.

Create validation rule in Salesforce Classic Click Setup. Click Customize | [the object you need to modify] | Validation Rules. Click New. Enter the Validation Rule name. Set the Validation Formula as per the suggestion above, feel free to adapt to your needs. Set the error message that the User will receive.