Prerequisite: You need to set the Field-Level Security on a custom component before you can view it in your page layout section.
Once you set the field-level security on a custom component, you need to edit the page layout on your Salesforce App to view it on an object record (like Accounts or Opportunities.)
Edit the page layout
To edit the page layout for a Salesforce object:
- From your Salesforce account, at the top navigate to tab that you want to assign the new Page layout. For illustrative purposes, we're editing the Accounts page layout.
- Click on any record under the Accounts tab.
- Click the Quick Access Menu icon to the right.
- Click Edit Layout.
- From the "Account Layout" drag the custom field element to the header or line segment of the Accounts page.
Example: drag the Balance field to the Account Information header section.
- From the top left of the layout editor, click Save.
Once you've added a custom field on an Account record, it will appear in all Account records.