Scenario
Add the related Project/Job messages under Customer record > Communication tab.
Solution
First, create a saved search that will be used as a sublist:
1. Navigate to Reports > Saved Searches > All Saved Searches > New.
2. Select Project.
3. Under Criteria tab > Standard subtab > Leave the criteria blank/empty.
4. Under Results tab > Columns subtab, add the following fields:
-- Name
-- Internal ID
-- Messages Fields... > click Add Multiple > select Author, Date, Message, Primary Recipient, Subject > click Add
It should look like this:
5. Under Available Filters tab > add Customer > mark Show in Filter Region checkbox.
6. Rename the search > Save & Run.
NOTES:
- You may add criteria such as Inactive is No, etc.
- You may add additional columns under Results tab based on what you want to see on the sublist.
- Adding Additional Filter 'Customer' is important to be able to use this search as sublist.
Then, add the created saved search as sublist:
1. Navigate to Customization > Forms > Sublists.
2. Under Entity tab, add the below:
-- Search = <the name of the saved search we just created above>
-- Label = Project/Job Communication
-- Tab = Communication
-- Customer = Yes
3. Click Save
Go to a sample customer record and verify that the sublist has been added.