You can add an override to any security category that will allow the specified sub-admin or junior admin group access to content in that security category. To do this:
  1. Select Setup > Security Categories
  2. Search for the security category for the content and click on the security category's name
  3. Select the Category Permissions tab
  4. Select the appropriate permission option for the content (For example TeamRaiser Management, Donation Form Management, or Contact Management)
  5. Click Add and override
  6. Select the appropriate Group Type for your admin group > your group under Group Name
  7. Select the desired permission level
  8. Click Save
  9. Repeat as needed for different permission options